Photovoltaic cell with silole-containing co-polymer

The present invention relates not only to photovoltaic cells using siror-containing polymers, but also to related components, systems and methods. (Cross-reference of related applications) Under 35 USC 119, this application claims priority to US Patent Provisional Application No. 60 / 850,963 filed October 11, 2006, with reference to the entire contents of such provisional application. Incorporate into the book.

Photocells are widely used to convert energy in the form of light into energy in the form of electricity. A typical photovoltaic cell includes a photoactive material placed between two electrodes. In general, light passes through one or both of those electrodes and interacts with the photoactive material. As a result, the ability of one or both electrodes to transmit light (eg, light of one or more wavelengths absorbed by a photoactive material) may limit the overall efficiency of the photovoltaic cell. In many photovoltaic cells, a film of semiconductor material (eg, indium tin oxide) is used to form electrodes through which light passes. The reason is that semiconductor materials are less conductive than conductive materials, but semiconductor materials can transmit more light than many conductive materials.

<p num="0003"><patcit num="1"><text>U.S. Patent Application No. 11 / 486,536</text></patcit><patcit num="2"><text>U.S. Patent Application No. 10 / 723,554</text></patcit><patcit num="3"><text>U.S. Patent Application No. 10 / 558,878</text></patcit><patcit num="4"><text>U.S. Pat. No. 7,022,910</text></patcit></p>

<p num="0004"><nplcit num="1"><text>Coppo et al., Macromolecules, Vol. 36, pp. 2705-2711 (2003)</text></nplcit><nplcit num="2"><text>Kurt et al. (Kurt et al.), J. Heterocycl. Chem. Volume 6, p. 629 (1970)</text></nplcit><nplcit num="3"><text>Usta et al., J. Am. Chem. Soc. Vol. 128 (28), pp. 9034-9535 (2006)</text></nplcit></p>

<p num="0005"> The present invention relates not only to photovoltaic cells using silol-containing polymers (eg, polymers containing silacyclopentadithiophene moieties), but also to related components, systems and methods.</p>

<p num="0006"> One aspect of the invention relates to a combination of new monomers that produce a polymer, which has properties suitable for use as a charge carrier in the active layer of a photovoltaic cell.</p><p num="0007"> In one aspect, the invention features a type of copolymer comprising at least two comonomer, at least one such comonomer being silacyclopentadithiophene. In another aspect, the invention comprises a first comonomer repeating unit and a first comonomer repeating unit. It is characterized by a polymer containing a second comonomer repeating unit that is different from the unit. The first comonomer repeating unit contains the silacyclopentadithiophene moiety of the following formula (1).</p><p num="0008"><chemistry num="1"><img id="000002" he="33" wi="146" file="JP5773568B2_D0001.tif" img-format="tif" img-content="drawing" /></chemistry></p><p num="0009">R₁, R₂, R₃And R₄H, C individually₁~ C₂₀Alkyl, C₁~ C₂₀Alkoxy, C₃~ C₂₀Cycloalkyl, C₁~ C₂₀Heterocycloalkyl, aryl, heteroaryl, halo, CN, OR, C (O) R, C (O) OR or SO₂R, where R is H, C₁~ C₂₀Alkyl, C₁~ C₂₀Alkoxy, aryl, heteroaryl, C₃~ C₂₀Cycloalkyl or C₁~ C₂₀Heterocycloalkyl. The second comonomer repeating unit is the silacyclopentadithiophene moiety, benzothiaziazole moiety, thiathiazoloquinoxaline moiety, cyclopentadithiophene moiety, cyclopentadithiophene oxide moiety, benzoisothiazole moiety, benzothiazole moiety of the formula (1). Part, thiophene oxide part, thienothiophene part, thienothiophene oxide part, dithienothiophene part, dithienothiophene oxide part, tetrahydroisoindole part, fluorene part, fluorenone part, thiazole part, selenophene part, silol part, thiazolothiazole part , Cyclopentazithiazole moiety, naphthothiaziazole moiety, thienopyrazine moiety, oxazole moiety, imidazole moiety, pyrimidine moiety, benzoxazole moiety, or benziimidazole moiety.</p><p num="0010"> In another aspect, the invention features a polymer comprising a first comonomer repeating unit and a second comonomer repeating unit that is different from the first comonomer repeating unit. The first comonomer repeating unit contains the silacyclopentadithiophene moiety of the above formula (1). The second comonomer repeating unit is C₁~ C₂₀Alkyl, C₁~ C₂₀Alkoxy, C₃~ C₂₀Cycloalkyl, C₁~ C₂₀Heterocycloalkyl, aryl, heteroaryl, halo, CN, OR', C (O) R', C (O) OR' or SO₂It contains a thiophene moiety substituted with R'or a thiophene moiety condensed with a 1,4-dioxane moiety, where R'is H, C.₁~ C₂₀Alkyl, C₁~ C₂₀Alkoxy, aryl, heteroaryl, C₃~ C₂₀Cycloalkyl or C₁~ C₂₀Heterocycloalkyl.</p><p num="0011"> In another aspect, the invention features a polymer containing a first comonomer repeating unit and a second comonomer repeating unit that is different from the first comonomer repeating unit. The first comonomer repeating unit has a silacyclopentadithiophene moiety of the above formula (1). The second comonomer repeat unit is not the unsubstituted thiophene moiety.</p><p num="0012"> In yet another aspect, the invention features an article comprising a first electrode, a second electrode, and a photoactive material disposed between the first and second electrodes. The photoactive material contains the above polymer. Such an article is configured as a photovoltaic cell.</p><p num="0013"> Embodiments can include one or more of the following features: In some embodiments, R₁And R₂Is individually C₁~ C₂₀Alkyl (eg, hexyl).</p><p num="0014"> In some embodiments, the second comonomer repeating unit is the benzothiasiazole moiety of formula (2), the thiadiazoloquinoxalin moiety of formula (3), the cyclopentadithiophene dioxide moiety of formula (4), the formula. Cyclopentadithiophene monoxide moiety in (5), benzoisothiazole moiety in formula (6), benzothiazole moiety in formula (7), thiophene dioxide moiety in formula (8), cyclopentadithiophene dioxide in formula (9) Part, cyclopentadithiophene tetraoxide moiety of equation (10), thienothiophene moiety of equation (11), thienothiophene tetraoxide moiety of equation (12), dithienothiophene moiety of equation (13), of equation (14) Dithienothiophene dioxide moiety, dithienothiophene tetraoxide moiety of formula (15), tetrahydroisoindole moiety of formula (16), thienothiophene dioxide moiety of formula (17), dithienothiophene dioxide moiety of formula (18), formula The fluorene moiety of equation (19), the silol moiety of equation (20), the cyclopentadithiophene moiety of equation (21), the fluorenone moiety of equation (22), the thiazole moiety of equation (23), the serenophene moiety of equation (24), The thiazolothiazole moiety of formula (25), the cyclopentadithiazole moiety of equation (26), the naphthothiazazole moiety of equation (27), the thienopyrazine moiety of equation (28), the oxazole moiety of equation (29), the equation (30). Includes an imidazole moiety of, a pyrimidine moiety of formula (31), a benzoxazole moiety of formula (32), or a benziimidazole moiety of formula (33).</p><p num="0015"><chemistry num="2"><img id="000003" he="245" wi="146" file="JP5773568B2_D0001.tif" img-format="tif" img-content="drawing" /></chemistry></p><p num="0016"><img id="000004" he="103" wi="146" file="JP5773568B2_D0001.tif" img-format="tif" img-content="drawing" /></p><p num="0017">In equations (2) to (33), X and Y are CH individually.₂, O or S, R₅And R₆H, C individually₁~ C₂₀Alkyl, C₁~ C₂₀Alkoxy, C₃~ C₂₀Cycloalkyl, C₁~ C₂₀Heterocycloalkyl, aryl, heteroaryl, halo, CN, OR, C (O) R, C (O) OR or SO₂R, where R is H, C₁~ C₂₀Alkyl, C₁~ C₂₀Alkoxy, aryl, heteroaryl, C₃~ C₂₀Cycloalkyl or C₁~ C₂₀Heterocycloalkyl, R₇And R₈H, C individually₁~ C₂₀Alkyl, C₁~ C₂₀Alkoxy, aryl, heteroaryl, C₃~ C₂₀Cycloalkyl or C₃~ C₂₀Heterocycloalkyl.</p><p num="0018"> In some embodiments, the second comonomer repeat unit comprises the benzothiadiazole moiety of formula (2) and is R.₅And R₆Are each H. In some embodiments, the second comonomer repeat unit comprises the thiazole moiety of formula (23), R.₅Is a hexyl.</p><p num="0019"> In some embodiments, the polymer further comprises a third comonomer repeat unit that is different from the first and second comonomer repeat units. The third comonomer repeat unit can include a thiophene moiety (eg, an unsubstituted thiophene moiety, or a hexyl-substituted thiophene moiety).</p><p num="0020"> In some embodiments, the polymer can be an electron donor material or an electron acceptor material. In some embodiments, the polymer is</p><p num="0021"><chemistry num="3"><img id="000005" he="148" wi="146" file="JP5773568B2_D0001.tif" img-format="tif" img-content="drawing" /></chemistry></p><p num="0022">It is possible that n is an integer greater than 1. In some embodiments, the photovoltaic cell is a series photovoltaic cell. In some embodiments, the photoactive material comprises an electron acceptor material. In some embodiments, the electron acceptor material is fullerene (eg, C61-phenyl-butyrate methyl ester, PCBM).</p><p num="0023"> In some embodiments, the polymer and electron acceptor material can each have a LUMO energy level. The LUMO energy level of the polymer can be a negative number that is at least about 0.2 eV (eg, at least about 0.3 eV) lower than the LUMO energy level of the electron acceptor material.</p><p num="0024"> In some embodiments, the device can be an organic semiconductor device. In certain embodiments, the device comprises a group of field effect transistors, photodetectors, photovoltaic detectors, imaging devices, light emitting diodes, laser devices, conversion layers, amplifiers and radiators, storage devices, and electrochromic devices. It can be a member selected from.</p><p num="0025"> The embodiment can provide one or more of the following advantages: In some embodiments, the use of polymers containing silacyclopentadithiophene moieties can be advantageous. The reason is that the silacyclopentadithiophene portion is electromagnetic. This is because it can contribute to the movement of the maximum absorption wavelength toward the red or near-infrared region of the spectrum. Incorporating such polymers into photoelectricity can increase the current and efficiency of photovoltaic cells.</p><p num="0026"> In some embodiments, a polymer containing a substituted fullerene, or a substituted monomer repeating unit (eg, substituted with a long-chain alkoxy group such as an ethylene oxide oligomer or a fluorinated alkoxy group) is improved in an organic solvent. It can have a good solubility and can form a morphologically improved photoactive layer.</p><p num="0027"> In some embodiments, the polymer containing the siol moiety can absorb light of relatively long wavelengths and have improved solubility in organic solvents. In some embodiments, polymers containing a siol moiety can be used to prepare electron acceptor materials with improved semiconductor properties.</p><p num="0028"> In some embodiments, the polymer-containing photovoltaic cell can have a relatively ideal bandgap for the intended purpose. In some embodiments, high battery voltage photovoltaic cells can be produced, which results in negative numbers of polymer HOMO levels that are at least about 0.2 electron volts higher than the LUMO or conduction band of the electron acceptor material.</p><p num="0029"> In some embodiments, in a photocell containing the polymer, electrons can move relatively quickly and efficiently to the electron acceptor material, thereby allowing the donor LUMO to conduct the electron acceptor material. Negative numbers that are at least about 0.2 electron volt (eg, at least about 0.3 electron volt) lower than the band.</p><p num="0030"> In some embodiments, in a photocell containing the polymer, charge separation can be relatively fast, which results in relatively high charge mobility of positive or hole.^-4~10^-1cm²It is in the range of / Vs.</p><p num="0031"> In some embodiments, the polymer is either organic solvent soluble and / or film resistant. In some embodiments, the polymer is optically non-scattering.</p><p num="0032"> In some embodiments, the polymer can be used in organic field effect transistors and OLEDs. Other features and advantages of the present invention will become apparent from the description, drawings and claims.</p>

<figref num="1">Sectional drawing of embodiment of a photovoltaic cell.</figref><figref num="2">The figure which outlines the system which contains one electrode between two photoactive layers.</figref>

Similar reference symbols in various drawings represent similar elements. FIG. 1 shows a cross-sectional view of the photovoltaic cell 100, showing a substrate 110, a positive electrode 120, a hole carrier layer 130, an active layer 140 (containing an electron acceptor material and an electron donor material), a hole blocking layer 150, a negative electrode 160, and The substrate 170 is included.

Generally, during use, light hits the surface of the substrate 110 and passes through the substrate 110, the positive electrode 120, and the hole carrier layer 130. The light then interacts with the active layer 140, transferring electrons from the electron donor material (eg, the polymer above) to the electron acceptor material (eg, PCBM). Let me. The electron acceptor material then transfers electrons to the negative electrode 160 through the hole blocking layer 150, and the electron donor material transfers holes to the positive electrode 120 through the hole carrier layer 130. The negative electrode 160 and the positive electrode 120 are electrically connected via an external load, and electrons are transferred from the negative electrode 160 to the positive electrode 120 through the applied load.

The electron acceptor material of the active layer 140 can include fullerenes. In some embodiments, the active layer 140 can include one or more unsubstituted fullerenes and / or one or more substituted fullerenes. An example of an unsubstituted fullerene is C₆₀, C₇₀, C₇₆, C₇₈, C₈₂, C₈₄And C₉₂including. Examples of substituted fullerenes are C.₁~ C₂₀Fullerene substituted with alkoxy, and the alkoxy is optionally C₁~ C₂₀Alkoxy or halo (eg (OCH)₂CH₂)₂OCH₃Or OCH₂CF₂OCF₂CF₂OCF₃) Includes fullerenes, or PCBMs further substituted. Without being bound by theory, fullerenes substituted with long-chain alkoxy groups (eg ethylene oxide oligomers) or fluorinated alkoxy groups have improved solubility in organic solvents and are morphologically improved. It is believed that a photoactive layer can be formed.

In some embodiments, the electron acceptor material can include polymers (eg, homopolymers or copolymers). The polymers described herein are at least two identical or dissimilar monomer repeat units (eg, at least 5 monomer repeat units, at least 10 monomer repeat units, at least 50 monomer repeat units, at least 100 monomers. Contains repeating units, or at least 500 monomer repeating units). The copolymers described herein refer to polymers containing at least two comonomer with different structures. In some embodiments, the polymer used as the electron acceptor material can contain one or more monomer repeat units shown in Tables 1 and 2 below. Specifically, Table 1 shows examples of electron-donating monomer repeat units that can function as conjugated bonds. Table 2 shows examples of electron-withdrawing monomer repeating units. Note that depending on the substituent, the monomer repeating units shown in Table 1 can be electron-withdrawing, and the monomer repeating units shown in Table 2 can also be electron-donating. Preferably, the polymer used as the electron acceptor material contains an electron-withdrawing monomer repeating unit with a high molar percentage (eg, at least about 50%, at least about 60%, at least about 70%, at least about 80%, at least about about. 90%).

The electron donor material of the active layer 140 can include monomers (eg, homopolymers or copolymers). In some embodiments, the polymer used as the electron donor material can contain one or more monomer repeat units shown in Tables 1 and 2. Preferably, the polymer used as the electron donor material has a high molar percentage of electron-donating monomer repeat units (eg, at least about 50%, at least about 60%, at least about 70%, at least about 80%, at least about about. 90%). In some embodiments, the polymer is C on the ring.₁~ C₂₀Contains monomeric repeating units containing alkoxy, such alkoxy optionally C₁~ C₂₀Alkoxy or halo (eg (OCH)₂CH₂)₂OCH₃Or OCH₂CF₂OCF₂CF₂OCF₃) Is further replaced. Without being bound by theory, polymers containing monomer repeating units substituted with long-chain alkoxy groups (eg, ethylene oxide oligomers) or fluorinated alkoxy groups have improved solubility in organic solvents. It is believed that a morphologically improved photoactive layer can be formed.

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For the equations shown in Tables 1 and 2 above, X and Y are CHs individually.₂Can be O or S, R₁, R₂, R₃, R₄, R₅And R₆H, C individually₁~ C₂₀Alkylation (eg branched alkyl or perfluorinated alkyl), C₁~ C₂₀Alkoxy, C₃~ C₂₀Cycloalkyl, C₁~ C₂₀Heterocycloalkyl, aryl (For example, phenyl or substituted phenyl), heteroaryl, halo, CN, OR, C (O) R, C (O) OR or SO₂R, where R is H, C₁~ C₂₀Alkyl, C₁~ C₂₀Alkoxy, aryl, heteroaryl, C₃~ C₂₀Cycloalkyl or C₁~ C₂₀Can be heterocycloalkyl, R₇And R₈H, C individually₁~ C₂₀Alkyl, C₁~ C₂₀Alkoxy, aryl, heteroaryl, C₃~ C₂₀Cycloalkyl or C₃~ C₂₀Heterocycloalkyl.

The alkyl can be a saturated or unsaturated branched chain or a straight chain. C₁~ C₂₀Alkyl contains 1 to 20 carbon atoms (eg, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19). And 20 carbon atoms). An example of the alkyl moiety is -CH₃, -CH₂-, -CH₂= CH₂-, -CH₂-CH = CH₂And branch-C₃H₇including. Alkoxy can be branched or straight chain saturated or unsaturated. C₁~ C₂₀Alkoxy contains oxygen radicals and 1 to 20 carbon atoms (eg, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17). , 18, 19 and 20 carbon atoms). An example of the alkoxy moiety is -OCH₃And -OCH = CH-CH₃including. Cycloalkyl can be saturated or unsaturated. C₃~ C₂₀Cycloalkyl contains 3 to 20 carbon atoms (eg, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 and 20). Contains carbon atoms). Examples of cycloalkyl moieties include cyclohexyl and cyclohexene-3-yl. Heterocycloalkyl can also be saturated or unsaturated. C₃~ C₂₀Heterocycloalkyls include at least one cyclic heteroatom (eg, O, N and S) and 3 to 20 carbon atoms (eg, 3, 4, 5, 6, 7, 8, 9, 10, 11, Contains 12, 13, 14, 15, 16, 17, 18, 19 and 20 carbon atoms). Examples of heterocycloalkyl moieties include 4-tetrahydropyranyl and 4-pyranyl. Aryl can contain one or more aromatic rings. Examples of aryl moieties include phenyl, phenylene, naphthyl, naphthylene, pyrenyl, anthryl and phenanthryl. Heteroaryls can contain one or more aromatic rings, of which at least one contains at least one cyclic heteroatom (eg, O, N and S). Examples of heteroaryl moieties include frills, furylene, fluorenyl, pyrrolyl, thienyl, oxazolyl, imidazolyl, thiazolyl, pyridyl, pyrimidinyl, quinazolinyl, quinolyl, isoquinolyl and indolyl.

Alkyl, alkoxy, cycloalkyl, heterocycloalkyl, aryl and heteroaryl described herein include both substituted and unsubstituted moieties unless otherwise specified. Examples of substituents on cycloalkyl, heterocycloalkyl, aryl and heteroaryl are described in C.₁~ C₂₀Alkyl, C₃~ C₂₀Cycloalkyl, C₁~ C₂₀Alkoxy, aryl, aryloxy, heteroaryl, heteroaryloxy, amino, C₁~ C₁₀Alkylamino, C₁~ C₂₀Dialkylamino, arylamino, diarylamino, hydroxyl, halogen, thio, C₁~ C₁₀Alkylthio, arylthio, C₁~ C₁₀Includes alkylsulfonyls, arylsulfonyls, cyanos, nitros, acyls, acyloxys, carboxys and carboxylic acid esters. Examples of substituents on aryls are C₁~ C₂₀Contains all of the above substituents except alkyl. Cycloalkyl, heterocycloalkyl, aryl and heteroaryl also include a condensing group.

Monomers for preparing the polymers described herein may include non-aromatic double bonds and one or more asymmetric centers. Thus, such monomers can exist as racemic compounds and racemic mixtures, single enantiomers, individual diastereomers, diastereomer mixtures, and cis-or trans-isomer forms. All such isomer forms are considered.

The copolymer can be prepared by a method known in the art. For example, a copolymer is prepared by a cross- coupling reaction of one or more comonomer containing two alkylstannyl groups and one or more comonomer containing two halo groups in the presence of a transition metal catalyst. can do. As another example, by a cross-coupling reaction of one or more comonomers containing two borate groups and one or more comonomers containing two halo groups in the presence of a transition metal catalyst. Copolymers can be prepared. These comonomer can be prepared by the methods described herein, or Patent Document 1, Non-Patent Document 1 and Non-Patent Document 2 (these contents are incorporated herein by reference). It can be prepared by a method known in the art, such as the method described in.

Table 3 below shows the four exemplary polymers (ie, polymers 1-4) described in the section on Means for Solving the Problems. These polymers can have unique properties, which make them particularly suitable as charge carriers for the active layer of photovoltaic cells. Polymers 1 to 4 can be obtained by the methods described in Examples 2 to 5 below.

Table 3

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In general, one comonomer in the polymer described in the Means for Solving the Problems section is silacyclopentadithiophene. The advantage of a copolymer containing a silacyclopentadithiophene moiety is that its absorption wavelength can be moved towards the red and near infrared regions (eg, 650-800 nm) of the electromagnetic spectrum, which Not available for most other polymers. Incorporation of such copolymers into photoelectricity allows the photovoltaic cells to absorb light in this spectral range, thereby increasing the current and efficiency of the photovoltaic cells.

The polymers can be useful in the field of solar energy technology. The reason is that the bandgap is nearly ideal for photovoltaic cells (eg polymer-fullerene batteries). The HOMO level of the polymer is the photovoltaic cell (eg polymer-fuller) It can be positioned more accurately than the LUMO of the electron acceptor (for example, PCBM) in the Ren battery), and a higher battery voltage is possible. The polymer LUMO can be positioned more accurately than the conduction band of the electron acceptor in the photovoltaic cell, which allows electrons to move efficiently to the electron acceptor. For example, using a polymer with a bandgap of about 1.4-1.6 eV will significantly increase the battery voltage. Battery performance, especially efficiency, can benefit from both increased photocurrent and increased battery voltage, approaching and even exceeding 15% efficiency. The positive charge mobility of the polymer is relatively high, about 10^-4~10^-1cm²Can be in the range / Vs. In general, a relatively high positive charge mobility allows for relatively fast charge separation. The polymer can also be organic solvent soluble and / or film resistant. In addition, the polymer can be optically non-scattering.

Components of the photovoltaic cell other than the electron acceptor material and the electron donor material are known in the art, such as the components described in Patent Document 2, and the contents of such applications are described herein by reference. Is incorporated into.

In some embodiments, the polymer can be used as an electron donor or electron acceptor material in a system in which one common electrode is shared by two photovoltaic cells. Such a system is also known as a series photovoltaic cell. Examples of series photovoltaic cells are discussed in Patent Document 3 filed on November 29, 2005, the contents of such applications being incorporated herein by reference.

As an example, FIG. 2 is a schematic representation of a series photovoltaic cell 200, which has a substrate 210, three electrodes 220, 240 and 260, and two photoactive layers 230 and 250. The electrode 240 is shared between the photoactive layers 230 and 250 and is electrically connected to the electrodes 220 and 260. In general, the electrodes 220, 240 and 260 can be formed of a conductive material such as the material described in Patent Document 2. In some embodiments, one or more (ie, one, two or three) electrodes 220, 240 and 260 are mesh electrodes. In some embodiments, one or more electrodes 220, 240 and 260 are formed of a semiconductor material. Examples of semiconductor materials include titanium oxide, indium tin oxide, tin fluorinated, tin oxide and zinc oxide. In certain embodiments, one or more (ie, one, two or three) electrodes 220, 240 and 260 are formed of titanium dioxide. The titanium dioxide used to prepare the electrodes can be in any suitable form. For example, titanium dioxide can be in the form of interconnected nanoparticles. Examples of interconnected titanium dioxide nanoparticles are described, for example, in Patent Document 4, the contents of such patents being incorporated herein by reference. In some embodiments, at least one of the electrodes 220, 240 and 260 (eg, one, two or three) is a transparent electrode. As referred to herein, a transparent electrode is an incident light of a wavelength or wavelength range used during the operation of a photovoltaic cell, at least about 60% (eg, at least about 70%) of the thickness used for the photovoltaic cell. , At least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%) Electrodes made of permeable material. In certain embodiments, both electrodes 220 and 260 are transparent electrodes.

The photoactive layers 230 and 250 can each contain at least one semiconductor material. In some embodiments, the semiconductor material in the photoactive layer 230 has the same bandgap as the semiconductor material in the photoactive layer 250. In certain embodiments, the semiconductor material in the photoactive layer 230 has a different bandgap than the semiconductor material in the photoactive layer 250. Although not bound by theory, it is believed that the incident light that one photoactive layer did not absorb can be absorbed by the other photoactive layer, thereby maximizing the absorption of the incident light. .. In some embodiments, at least one of the photoactive layers 230 and 250 is an electron acceptor material (eg, PCBM or the polymer) and an electron donor material (eg, the polymer). -) And can be contained. In general, suitable electron acceptor and electron donor materials can be as described above. In certain embodiments, the photoactive layers 230 and 250 each contain an electron acceptor material and an electron donor material.

The substrate 210 can be formed of one or more suitable polymers, such as the polymers described in Patent Document 2. In some embodiments, an additional substrate (not shown in FIG. 2) can be placed on the electrode 260.

The photovoltaic cell 200 further contains a hole carrier layer (not shown in FIG. 2) and a hole blocking layer (not shown in FIG. 2), such as the layer described in Patent Document 2. Can be done.

Although photovoltaic cells have been described above, in some embodiments, the polymers described herein can be used in other devices and systems. For example, electric field effect transistors, photodetectors (eg, infrared photodetectors), photoelectromotive power detectors, imaging devices (eg, RGB imaging devices for cameras or medical imaging systems), light emitting diodes (LEDs) (eg, for example. Organic LEDs, or infrared or near-infrared LEDs), laser devices, conversion layers (eg, layers that convert visible emission to infrared emission), amplifiers and radiators for telecommunications (eg, fiber doping agents), These polymers can be used in storage devices (eg, holographic storage devices) as well as suitable organic semiconductor devices such as electrochromic devices (eg, electrochromic displays).

The following examples are exemplary and are not intended to be limiting. (Example 1) Synthesis of bis- (5,5'-trimethylstannyl) -3,3'-di-n-hexyl-cilylene-2,2'-dithiophene

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0.638 g (1.76 mmol) of 3,3'-di-n-hexylsilylene-2,2'-dithiophene (prepared according to the procedure described in Non-Patent Document 3 and the content of such literature is herein by reference. Was dissolved in freshly distilled 20 mL anhydrous THF. The solution was purged with nitrogen for 15 minutes and cooled to -78 ° C. 4.00 mL of n-butyllithium added to hexane (10 mmol) was added dropwise to this solution. The solution was allowed to react at this temperature for 2 hours. Then, the solution was heated to room temperature and left for another two and a half hours for reaction. Then, after lowering the temperature of the solution to 78 ° C., 12.00 mL (12.00 mmol) of trimethyltin chloride added to hexane was added dropwise to this solution. The reaction solution was stirred at 78 ° C. for an additional 2 hours. Then, the solution was heated to room temperature and left for another 16 hours for reaction. As soon as the reaction was completed, 100 mL of distilled water was added and the solution was extracted with toluene (3 x 60 mL). The integrated organic phase was washed with distilled water (3 x 150 mL) and dried over sodium sulfate. Rotate under vacuum The organic solvent was removed by evaporation. The residue was dissolved in triene and quickly passed through a silica gel pad pretreated with triethylamine. The organic solvent was removed under vacuum to give the title compound (1.048 g). The yield was about 86.50%. CDCl₃Inside¹1 H NMR: 7.00 (m, 2H), 1.25 to 1.42 (m, 16H), 0.86 to 0.94 (m, 10H) and 0.38 (m, 18H).

(Example 2) Bis- (5,5'-trimethylstannyl) -3,3'-di-n-hexyl-cilylene-2,2'-dithiophene and 4,7-dibromo-2,13-benzo Polymerization with thiadiazole

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0.353 g (0.513 mmol) of bis- (5,5'-trimethylstannyl) -3,3'-di-n-hexyl-cilylene-2,2'-dithiophene and 0.135 g (0.500 mmol) (monomer ratio) = 1.025) of 4,7-dibromo-2,1,3-benzothiadiazole was dissolved in 12 mL of anhydrous toluene. After purging the solution with nitrogen, 12.55 mg (0.014 mmol) of tris (dibenzylideneacetone) dipalladium (0) and 28.80 mg (0.110 mmol) of triphenylphosphine were added. The solution was purged with nitrogen for an additional 15 minutes. Then, the solution was heated to 110 to 120 ° C. and left for 40 hours for reaction. As soon as the reaction was completed, the solvent was removed by rotary evaporation. The resulting residue was dissolved in about 30 mL of chlorobenzene. After injecting this chlorobenzene solution into 600 mL of methanol, the dark blue precipitate (crude polymer product) obtained accordingly was recovered by filtration. The recovered solid was redissolved in about 40 mL of chlorobenzene under heating. This chlorobenzene solution was filtered through a 0.45 μ membrane and injected into 600 mL of methanol. The resulting dark blue polymer product was recovered by filtration, washed with methanol (3 x 100 mL) and dried under vacuum.

The dried polymer product was redissolved in 60 mL hot chlorobenzene and injected into 60 mL aqueous solution of 7.5% sodium diethyldithiocarbamate trihydrate (DDC). The solution was purged with nitrogen for 15 minutes. The resulting two-phase mixed solution was heated at about 80 ° C. and stirred vigorously under nitrogen for 15 hours. The organic phase was washed with hot distilled water (3 x 60 mL) and then slowly injected into 800 mL of methanol. The precipitate was collected by filtration. The recovered polymer product was first placed in a Soxhlet extractor and extracted with acetone and methanol for 12 hours each. The polymer product was then recovered and dried. The molecular weight distribution of the polymer product was analyzed by GPC column using HPLC on a polystyrene basis (HPLC instrument: Agilent Technologies., Model number 1090M. HPLC column: PL gel 10M mixture B. used Solvent: Chlorobenzene). The measured values of the molecular weight distribution are as follows. M_n= 4, 000 and M_w= 5,000. λ_max.(nm) (in chlorobenzene) = 641 nm. λ_max.(nm) (thin film) = 673 nm.

HOMO (eV) =-5.47 (by electrochemical measurement), LUMO (eV) =-3.69 (by electrochemical measurement), and bandgap value 1.78eV (calculated from electrochemical measurement results).

(Example 3) Bis- (5,5'-trimethylstannyl) -3,3'-di-n-hexyl-cilylene-2,2'-dithiophene and 3-hexyl-2,5-dibromo-thiophene Polymerization with

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0.353 g (0.513 mmol) of bis- (5,5'-trimethylstannyl) -3,3'-di-n-hexyl-cilylene-2,2'-dithiophene and 0.163 g (0.500 mmol) (monomer ratio) = 1.025) of 3-hexyl-2,5-dibromothiophene was dissolved in 12 mL of anhydrous toluene. After purging the solution with nitrogen, 12.55 mg (0.014 mmol) of tris (dibenzylideneacetone) dipalladium (0) and 28.80 mg (0.110 mmol) of triphenylphosphine were added. The solution was purged with nitrogen for an additional 15 minutes. Then, the solution was heated to 110 to 120 ° C. and left for 40 hours for reaction. As soon as the reaction was completed, the solvent was removed by rotary evaporation. The resulting residue was washed with methanol (50 mL x 3) and then with acetone (3 x 50 mL). The residue of the polymer product was recovered as a dark red to purple solid. The recovered polymer product was redissolved in about 60 mL of chloroform under heating. After filtering this chloroform solution with a 0.45 μ membrane, the solvent was removed by rotary evaporation under vacuum. The polymer product was then dried under vacuum.

The dried polymer product was redissolved in 60 mL of hot toluene. This solution was injected into 60 mL of 7.5% aqueous DDC solution. The solution was purged with nitrogen for 15 minutes. The resulting two-phase mixed solution was heated at about 80 ° C. and vigorously stirred for 12 hours under nitrogen protection. Then, the organic phase was washed with hot distilled water (3 × 60 mL), and then the organic phase was recovered and dried over anhydrous magnesium sulfate. The solvent was removed to give a solid polymer product. The solid polymer product was run in a Soxhlet extractor and sequentially extracted with methanol and acetone for 12 hours each. Finally, the polymer product was recovered and dried. The molecular weight distribution of the polymer is based on polystyrene by GPC column using HPLC. (HPLC instrument: manufactured by Agilent Technologies., Model number 1090M. HPLC column: PL gel 10M mixture B. Solvent used: chlorobenzene). The measured values of the molecular weight distribution are as follows. M_n= 10,000 and M_w= 13,500. λ_max.(nm) (in chlorobenzene) = 501 nm. λ_max.(nm) (thin film) = 503 nm.

(Example 4) Bis- (5,5'-trimethylstannyl) -3,3'-di-n-hexyl-cilylene-2,2'-dithiophene and 4,7-dibromo-2,13-benzo Polymerization of thiadiazole with 3-hexyl-2,5-dibromo-thiophene

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0.310 g (0.450 mmol) of bis- (5,5'-trimethylstannyl) -3,3'-di-n-hexyl-cilylene-2,2'-dithiophene and 0.068 g (0.225 mmol) (monomer ratio) = 1.025) of 4,7-dibromo-2,1,3-benzothiadiazole and 0.073 g (0.225 mmol) of 3-hexyl-2,5-dibromothiophene (monomer ratio = 2: 1: 1). It was dissolved in 12 mL of anhydrous toluene. After purging the solution with nitrogen, 12.55 mg (0.014 mmol) of tris (dibenzylideneacetone) dipalladium (0) and 28.80 mg (0.110 mmol) of triphenylphosphine were added. The solution was purged with nitrogen for an additional 15 minutes. Then, the solution was heated to 110 to 120 ° C. and left for 40 hours for reaction. As soon as the reaction was completed, the solvent was removed by rotary evaporation. The resulting residue was dissolved in about 30 mL of chlorobenzene. After injecting this solution into 600 mL of methanol, a dark blue to black precipitate was collected by filtration. The recovered solid polymer product was then redissolved in about 40 mL of chlorobenzene under heating. This chlorobenzene solution was filtered through a 0.45 μ membrane and then injected into 600 mL of methanol. The dark blue to black polymer product was recovered again by filtration. The solid polymer product was washed with methanol (3 x 100 mL) and dried under vacuum.

The dried polymer product was redissolved in 60 mL of hot chlorobenzene and injected into 60 mL of 7.5% aqueous DDC solution. The solution was purged with nitrogen for 15 minutes. The resulting two-phase mixed solution was heated at about 80 ° C. and stirred vigorously for 15 hours under nitrogen protection. The organic phase was then washed with hot distilled water (3 x 60 mL). The chlorobenzene solution was slowly injected into 800 mL of methanol, and the resulting precipitate was collected by filtration. The recovered solid polymer product was placed in a Soxhlet extractor and sequentially extracted with acetone and methanol for 12 hours each. The polymer product was then recovered and dried. The molecular weight distribution of the polymer was analyzed by GPC column using HPLC with respect to polystyrene (HPLC instrument: Agilent Technologies (Agil)). ent Technologies.), Model number 1090M. HPLC column: PL gel 10M mixture B. Solvent used: Chlorobenzene). The measured values of the molecular weight distribution are as follows. M_n= 7,500 and M_w= 10,400. λ_max.(nm) (in chlorobenzene) = 595 nm. λ_max.(nm) (thin film) = 649 nm.

(Example 5) Bis- (5,5'-trimethylstannyl) -3,3'-di-n-hexyl-cilylene-2,2'-dithiophene and 5,5'-bis (5-bromo- 2-Thienyl) -4,4'-dihexyl-2,2'-polymerization with bithiazole

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0.045 g (0.0654 mmol) of bis- (5,5'-trimethylstannyl) -3,3'-di-n-hexyl-cilylene-2,2'-dithiophene in a 100 mL Schlenk flask, 0.043 g (0.0654 mmol) 5,5'-bis (5-bromo-2-thienyl) -4,4'-dihexyl-2,2'-bitiazole and 1.0 mg (0.00109 mmol) Pd₂dba₃And 2.0 mg (0.0076 mmol) PPh₃And filled. The flask was evacuated and refilled with argon three times. The solid was dissolved in 3 mL of o-xylene and the solution was heated to 95 ° C for 24 hours. The solution was then cooled and injected into 500 mL of MeOH agitated and filtered. The resulting black precipitate was washed with MeOH and dried under vacuum to give a brown solid (0.069 g). Mn = 3.7 kDa. Mw = 4.6kDa.

(Example 6) Manufacture of a solar cell Using polymers 1 and 2, solar cells were made on glass / ITO substrates as follows. That is, a PEDOT (Bytron PH) layer to be used as an electron blocking layer was obtained by doctor braiding of an isopropanol solution on ITO. Subsequently, the PEDOT layer was baked to improve its solvent resistance. The mixture of test polymer (ie polymer 1 or 2) and PCBM in a weight ratio of 1: 1 is then CHCl.₃Alternatively, an active layer, which was added to o-dichlorobenzene, was applied to the upper part of the PEDOT layer. The device was completed by applying the upper electrode by high vacuum deposition of LiF / aluminum double layer. The current density-voltage (JV) characteristics of the device were evaluated in a nitrogen atmosphere using a Keithley SMU2400 source measure unit. 0.1 W / cm using filter wave xenon light from Oriel solar simulator²It was close to the AM1.5G spectrum of. The results show that the film formed by polymer 1 or 2 contains pinholes, and that solar cells containing polymer 1 or 2 have an efficiency of 0.7% or less.

Other embodiments are shown in the claims.