Low temperature method of making a zinc oxide coated article

Low temperature process for manufacturing an article coated with zinc oxide

Background of the invention

The present invention relates to a process of manufacturing a zinc oxide coating on a transparent substrate. More particularly, it refers to a chemical vapor deposition process of a zinc oxide coating on a transparent substrate in which the coating is modified to create a zinc oxide coating having a combination of desired properties.

The growth of zinc oxide coatings by CVD has been published in the scientific literature. For example, Smith, Frank TJ, & quot; Metalorganic chemical vapor deposition of oriented ZnO films over large areas & quot ;, Applied Physics Letters, Vol. 43, No. 12 (1983) p. 1108-1110, describes a method of depositing organic metal chemical vapor to prepare ZnO films oriented on the c-axis in a system similar to that commercially available for the deposit of SiO2. The resulting films are said to have a very uniform thickness and adhere to various substrates.

Gerfin and Dahmen in CVD of Nonmetals (WS Rees, Jr. ed., VCH Publishers, Inc., New York, NY, 1996), chapter 3, p. 180-185, describe the work of a number of researchers on the use of various chemical preparation techniques to form zinc oxide films. The use of dialkylcinc compounds and various oxygen-containing compounds is discussed.

The deposition of zinc oxide films has also been described in the patent literature.

U.S. Pat. No. 4,751,149 granted to Vijaykumar, P., et al. describes a static deposition process at low temperature (200 ° C or less), low pressure (0.3 kPa or less) for zinc oxide films, using an organocinc compound and water transported in an inert gas. The resulting zinc oxide film is said to have a low resistivity that can be varied by the addition of an element of group 13.

U.S. Pat. No. 4,990,286 and Solar Cells, 30 (1991) 437-450 granted to Gordon, R., et al. describes the deposition of fluorine-doped zinc oxide films by chemical vapor deposition from vapor mixtures of compounds containing zinc, oxygen and fluorine. The films produced are said to be electrical conductors, transparent to visible light, reflective to infrared radiation and absorb ultraviolet light. The temperature sensitive substrates are said to be suitable with the process of the subject invention.

U.S. Pat. 5,306,522 describes procedures for coating a substrate, particularly substrates that include hidden surfaces, coated with zinc oxide-containing coatings. The methods described include the elements of contacting a substrate with a zinc oxide precursor, preferably keeping the substrate coated with the precursor under conditions that balance the coating, then oxidizing the precursor to form a zinc oxide-containing coating. Coated substrates are also described by the method for use in various applications.

U.S. Pat. 5,407,743, which is related to US Pat. No. 5,306,522 mentioned above, includes additional information particularly related to zinc oxide coated articles manufactured by the process described.

U.S. Pat. No. 6,416,814 granted to Giolando, D. describes the use of bound tin, titanium and zinc compounds as precursor compounds of a metal oxide in a process for producing high quality metal oxide coatings that come into contact with a heated substrate.

Document US-A-4 508 054 discloses a device for depositing a mineral oxide coating on a substrate by means of CVD, in which the reactive gases are made to be counterflowed, in order to ensure, by means of the turbulence effect , that there is an almost instantaneous mixture of reagents.

There is a growing demand for durable, transparent coated substrate materials, it would be desirable to have transparent substrate materials coated with zinc oxide that exhibit high transmittance to visible light, low emission capacity and / or solar control properties, conductivity High electrical / low sheet resistance and could be manufactured in a cost-effective way.

Brief description of the figures

Various other objects, features and advantages attached to the present invention will be more fully appreciated since it will be better understood from the following detailed description when considered in relation to the attached figure.

The Figure is a schematic representation of the dynamic coating nozzle used in Example 21, according to the invention.

Summary of the invention

The present invention relates to a process of manufacturing a transparent article coated with low resistivity zinc oxide, comprising the features of claim 1. Preferred embodiments of this process are defined in the dependent claims.

Detailed description of the invention

The present invention provides a cost-effective method of manufacturing pyrolytic zinc oxide coatings at commercially viable growth rates on transparent substrate materials having a glass transition point, Tv (softening point) of less than 400 ° C. The present invention overcomes the previous obstacles of manufacturing said doped zinc oxide films on a variety of possible transparent substrate materials, the zinc oxide film being deposited at a substrate temperature below 400 ° C, preferably between 80 ° C and 400 ° C.

Although any suitable method of chemical vapor deposition at atmospheric pressure can be used in connection with the present invention, the deposition method disclosed in US Pat. nº

6,268,019 granted to Atofina Chemicals, Inc.

It has been shown that the '019 patent process can deposit metal oxide films of various kinds, at commercially useful growth rates, for example at more than 5 nm / s. The deposit procedure of the '019 patent also has the advantage of being able to vary the mixing time of the reactant materials which, in turn, allows the properties of, in this case, the zinc oxide coatings to be adjusted. In particular, the present invention demonstrates the benefits of using multiple precursor compounds whose benefits will be discussed in greater detail herein. Such zinc oxide coated products, when doped, are useful as examples of a transparent conductive oxide. Zinc oxide coatings without doping can be useful in various stacking configurations of the coating for purposes of matching the refractive index.

More specifically, possible applications of doped zinc oxide coatings manufactured by the process of the present application include, without limitation: Organic photovoltaic (OPV) and thin film photovoltaic devices, flat panel displays, solid state lighting (LED and OLED), touch panel displays, transparent thin film resistors (TFT) that are applicable in RFID markers and integrated circuits, as well as low-capacity coating and solar control coating piles.

Suitable compounds containing zinc include, without limitation, compounds of the general formula R1R2Znlz or R1R2Zn- [R3R4N (CHR5) n (CH2) m (CHR6) nNR7R8], wherein R1-8 may be the same or different alkyl groups or aryl such as methyl, ethyl, isopropyl, n-propyl, n-butyl, sec-butyl, phenyl or substituted phenyl, and may include one

or more fluorine-containing substituents, L is a commercial neutral oxygen-based ligand such as tetrahydrofuran, methyl trihydrofuran, furan, diethyl or dibutyl ether, methyl tert-butyl ether or dioxane and z = 0-2. R5 and R6 can be H or alkyl or aryl groups, n can be 0 or 1 and m can be 1-6 if n is 0, and m can be 0-6 if n is 1.

Other suitable zinc compounds may include a dialkyl zinc glycol alkyl ether of the formula:

R92Zn • [R10O (CH2) 2O (CH2) 2OR10], in which R9 is a saturated short chain organic group having 1 to 4 carbon atoms and R10 is a short chain saturated organic group having 1 to 4 4 carbon atoms Preferably, R9 is a methyl or ethyl group (C2H5-) and R10 is a methyl group (CH3-) and is called the diethylcinc (DEZ) diglyme having the formula:

Et2Zn • [CH3O (CH2) 2O (CH2) 2OCH3]

Other tridentate ligands capable of chelating the dialkylcinc moiety that may be useful in connection with the present invention include: Compounds of the formula [R11C (OR12) 3], wherein R11 is H or a saturated short chain organic group having 1 to 4 carbon atoms or a phenyl group and R12 is a short chain saturated organic group that it has 1 to 4 carbon atoms as described above, in which R11 and R12 may be the same or different triamine ligands of the formula [R132N (CH2) 2N (R14) (CH2) 2NR132], in which R13 it is a saturated short chain organic group that has 1 to 4 carbon atoms, and compounds in which R14 = a phenyl group (C6H5) or a substituted phenyl group. Diphenylcinc compounds may also be useful in connection with the present invention.

Suitable oxygen-containing compounds include, among others: organic acetates, for example ethyl acetate (EtOAc), t-butyl acetate (t-BuOAc), alcohols (including perfluorinated derivatives), oxygen and water: 3 being 10

preferred are alcohols containing water or H2O.

An inert carrier gas, such as nitrogen, helium or the like can also be used as a component of the gaseous reactant stream of the present invention.

If the transparent substrate material is glass, it can be formed by any suitable procedure but preferably it is a continuous glass loop formed by the well-known floating glass process as described in US Pat. No. 3,356,474, 3,433,612, 3,531,274 and 3,790,361, each of which is incorporated herein by reference in its entirety.

Other suitable substrate materials include, without limitation, polymethylmethacrylate (pMMA), polyethylene terephthalate (PET), polyamides, polyimides, polylactic acid (PLA) and polycarbonate materials.

If desired, properties of at least electrical conductivity can be imparted to the zinc oxide coating by adding one or more doping materials to the one or more gaseous reactant streams. Suitable dopants include, without limitation, fluorine-containing compounds and precursors containing a group metal

13:

Suitable fluorine-containing compounds include, without limitation:

difluoromethane, 1,1-difluoroethane, 1,1,1,2-tetrafluoroethane, 1,1,1,2,2-pentafluoroethane, 1,1,1-trifluoroethane, 1,1,1,3,3-pentafluoropropane, fluoroethene, 1,1-diffuoroethene, 1,1,1,2,3,3,3-heptafluoropropane, 1,1,1,2,2,3,3heptafluoropropane, hexafluoropropene, 3,3,3-trifluoropropene, perfluorocyclopentene, perfluorobutadiene, 1,1,1,3,3,3-hexafluoro-2-propanol, 1,1,1,3,3,3-hexafluoro-2-methyl-2-propanol, hexafluoropropene oxide, 2,2, 3,4,4,4-hexafluoro-1-butanol, 1,1,2,2,3,4-hexafluoro-3,4-bis (trifluoromethyl) cyclobutane, hexafluoro-2-butyne, hexafluoroacetone, hexafluoroglutaric anhydride, trifluoroacetic anhydride, trifluoroacetyl chloride, 2,2,2trifluoroethanol, 1, 1,1-trifluoroacetone, trifluoromethane, 1,1,1-trifluoro-2-propanol, 3,3,3-trifluoropropionic acid, 3,3,3-trifluoropropino, trifluoroamine, hydrogen fluoride, trifluoroacetic acid, 1,1, 1,3,3-pentafluorobutane and 1,1,1,2,3,4,4,5,5,5-decafluoropentane.

Suitable precursors containing a group 13 metal include those of the general formula R15 (3-n) MR16n or R15 3M (L), wherein M = one of B, Al, Ga, In or Tl, R15 is a group alkyl or aryl or halide or alkoxide, R16 is a group H, alkyl, aryl, halide or diketonate with the formula (R17C (O) CR18C (O) R19), in which R17-19 can be the same or different and are groups H, alkyl or aryl (including cyclic and partially and perfluorinated derivatives), wherein L is a commercial neutral oxygen-based ligand, such as methyltrihydrofuran, tetrahydrofuran, furan, diethyl or dibutyl ether, dioxane, and n = 0-3. Me2Ga (hfac) (hfac = hexafluoroacetylacetonate, F3CC (O) CHC (O) CF3), Me2Ga (acac), Et2Al (acac) (acac = acetylacetonate, H3CC (O) CHC (O) CH3), and Et2AlCl are the compounds from group 13 preferred

It is preferred that zinc oxide films manufactured by the process of the present invention be doped with one or more of the doping materials mentioned above.

The following non-limiting examples illustrate certain aspects of the present invention.

Examples

Example 21 is an example according to the invention.

The APCVD apparatus used in examples 1-20 is similar to that described in US Pat. 6268019 B1. A key feature of the apparatus is the ability to control the mixing time of the gaseous reagents by introducing the vapors separately into the coating nozzle. In these experiments the nozzle for coating was composed of concentric tubes. a 0.95cm tube inserted into a 2.54cm tube by means of a compression adjustment that allows the length of the mixing zone to be adjusted, and an external 3.81cm tube connected to a waste gas blower for disposal of unreacted by-products and vapors. The films resulting from this nozzle configuration were circular with a diameter of approximately 3.81 cm.

The APCVD apparatus used in Example 21 is illustrated in the Figure and consists of a single slot 10 liner containing a mixing chamber 12, in which two separate streams of precursors can be combined in a controllable manner before they come into contact. with the surface of the substrate 14, which is supported on a nickel heating block 15. The first current is introduced through the head 16 and flows downwards through a distribution plate 17, while the second current is introduced through side inlet ports 18. The mixing chamber has a length of 3, 2 cm For a total nitrogen vehicle gas flow of 15 l / min, the mixing time of the two precursor streams is approximately 280 milliseconds. The deposited by-products and unreacted precursor vapors are removed by two slots for residual gases 20 (adjacent to the lining slot 22) connected

with a waste gas blower (not shown). The films resulting from this nozzle have a width of approximately 10 cm. The heated substrates can be transported below the nozzle to coat various lengths.

Examples 1-5 describe the zinc oxide deposit at 365 ° C and different proportions of H2O / Zn between 3 and 12, using the deposition procedure described above. Examples 6-10 describe the zinc oxide deposit at 280 ° C and different proportions of H2O / Zn between 3 and 12. Examples 11-15 describe the zinc oxide deposit at 190 ° C and different proportions of H2O / Zn: between 3 and 12. Examples 16-17 describe the zinc oxide deposit at 155 ° C and different proportions of H2O / Zn between 3 and 6. Examples 18-20 describe the ZnO deposit doped with Al at 200 ° C. Example 21 describes the deposit of ZnO doped with Ga at approximately 200 ° C. For all the previous examples, reactant concentrations were calculated based on the concentrations present when the currents were combined.

Examples 1-5

Borosilicate glass (1.1 mm thick) was heated to 365 ° C (measured by contact thermocouple on the substrate surface) on a nickel heating block. A mixture of 0.08 mol% Et2Zn · TEEDA gas (TEEDA = N, N, N ', N'-tetraethyl ethylenediamine) in 30 l / min of nitrogen carrier gas at a temperature of 180 ° C was introduced through of the primary chemical feed of the coating nozzle. In a separate feeder, a gas mixture of 0.24% mol to 0.97% mol, respectively of water vapor (evaporated in the vaporizer 1) in 2.2 l / min of nitrogen gas vehicle was introduced into the inner tube of the liner, which results in proportions of H2O / Zn between 3 and 12.

The internal feeding tube was adjusted in such a way that the length of the mixing zone was 15 cm. The nitrogen gas vehicle flows were chosen such that the speeds of the two feeders were approximately equal. Under these conditions, the velocity at the outlet of the nozzle of the casing was approximately 100 cm / s, which correlates with a mixing time of the reactant of approximately 150 ms (milliseconds).

The substrate was pre-dosed for 5 seconds with the water vapor gas mixture immediately before the flow of the Zn precursor began. Deposit rates varied between 8.87 nm / s and 6.45 nm / s, the highest deposit rate being the H2O / Zn ratio being 9 and the lowest deposit rate being the H2O / Zn ratio being 12 .

Examples 6-10

Borosilicate glass (1.1 mm thick) was heated to 280 ° C (measured by contact thermocouple on the surface of the substrate) on a nickel heating block. A mixture of 0.08 mol% of Et2Zn · TEEDA gas in 30 l / min of nitrogen vehicle gas at a temperature of 180 ° C was introduced through the primary chemical feed of the coating nozzle. In a separate feeder, a gas mixture of 0.24% mol to 0.97 [I]% mol, respectively of water vapor (evaporated in vaporizer 1) in 2.2 l / min of nitrogen gas vehicle is introduced into the inner tube of the liner, which results in proportions of H2O / Zn between 3 and 12.

The internal feeding tube was adjusted in such a way that the length of the mixing zone was 15 cm. The nitrogen gas vehicle flows were chosen such that the speeds of the two feeders were approximately equal. Under these conditions, the velocity at the outlet of the nozzle of the casing was approximately 100 cm / s, which correlates with a mixing time of the reactant of approximately 150 ms. The substrate was pre-dosed for 5 seconds with the steam immediately before the flow of the Zn precursor to the substrate began. The deposition rate varied between 9.28 nm / s and 6.84 nm / s, the highest deposition rate being the H2O / Zn ratio being 3 and the lowest deposition rate being the H2O / Zn ratio being 12 .

Examples 11-15

Borosilicate glass (1.1 mm thick) was heated to 190 ° C (measured by contact thermocouple on the surface of the substrate) on a nickel heating block. A mixture of 0.08 mol% of Et2Zn · TEEDA gas in 30 l / min of nitrogen vehicle gas at a temperature of 180 ° C was introduced through the primary chemical mouth of the coating nozzle. In a separate feeder, a gas mixture of 0.24% mol to 0.97% mol of water vapor (evaporated in vaporizer 1) in 2.2 l / min of nitrogen gas vehicle was introduced into the inner tube of the casing.

The inner feeder tube was adjusted so that the mixing zone was 15 cm long. The nitrogen gas vehicle flows were chosen such that the speeds of the two feeders were approximately equal. Under these conditions, the velocity at the outlet of the nozzle of the casing was approximately 100 cm / s, which correlates with a mixing time of the reactant of approximately 150 ms.

The substrate was pre-dosed for 5 seconds with the steam immediately before starting the flow of the

5 Zn precursor to the substrate. Deposit rates varied between 8.50 nm / s and 8.02 nm / s, the highest deposit rate being the H2O / Zn ratio being 9 and the lowest deposit rate being the H2O / Zn ratio being 6 .

Examples 16-17

Borosilicate glass (1.1 mm thick) was heated to 155 ° C (measured by contact thermocouple in the

10 substrate surface) on a nickel heating block. A mixture of 0.08 mol% of Et2Zn · TEEDA gas in 30 l / min of nitrogen vehicle gas at a temperature of 180 ° C was introduced through the primary chemical mouth of the coating nozzle. In a separate feeder, a gas mixture of 0.24% mol to 0.49% mol of water vapor (evaporated in vaporizer 1) in 2.2 l / min of nitrogen gas vehicle was introduced into the inner tube of the casing.

fifteen The internal feeding tube was adjusted in such a way that the length of the mixing zone was 15 cm. The nitrogen gas vehicle flows were chosen such that the speeds of the two feeders were approximately equal. Under these conditions, the velocity at the outlet of the nozzle of the casing was approximately 100 cm / s, which correlates with a mixing time of the reactant of approximately 150 ms.

twenty The substrate was pre-dosed for 5 seconds with the water vapor gas mixture immediately before the flow of the Zn and Ga precursor began. Deposit rates varied between 5.82 nm / s and 6.14 nm / s, the highest deposit rate being the H2O / Zn ratio being 3 and the lowest deposit rate being the H2O / Zn ratio being 6 .

25 Table 1

<dl><dt>Examples </dt><dd>Temp. deposit (ºC) H2O / Zn ratio Deposit Rate (nm / s)</dd></dl>

<dl><dt>1 </dt><dd> 365 6 7,71 </dd></dl>

<dl><dt>2 </dt><dd> 365 3 7,32 </dd></dl>

<dl><dt>3 </dt><dd> 365 9 7,87 </dd></dl>

<dl><dt>4 </dt><dd> 365 12 6,45 </dd></dl>

<dl><dt>5 </dt><dd> 365 6 6,84 </dd></dl>

<dl><dt>6 </dt><dd> 280 6 7,47 </dd></dl>

<dl><dt>7 </dt><dd> 280 3 9,28 </dd></dl>

<dl><dt>8 </dt><dd> 280 9 8,73 </dd></dl>

<dl><dt>9 </dt><dd> 280 12 6,84 </dd></dl>

<dl><dt>10 </dt><dd> 280 6 8,81 </dd></dl>

<dl><dt>11 </dt><dd> 190 6 8,02 </dd></dl>

<dl><dt>12 </dt><dd> 190 3 8,18 </dd></dl>

<dl><dt>13 </dt><dd> 190 9 8,50 </dd></dl>

<dl><dt>14 </dt><dd> 190 12 8,18 </dd></dl>

<dl><dt>15 </dt><dd> 190 6 8,34 </dd></dl>

<dl><dt>16 </dt><dd> 155 6 5,82 </dd></dl>

<dl><dt>17 </dt><dd> 155 3 6,14 </dd></dl>

As seen in the previous examples, the ZnO deposition rate was relatively consistent, at commercially viable depot rates, between 190 ° C and 365 ° C. As the substrate temperature drops below 190 ° C, a significant decrease in deposition rate was observed.

Example 18

Borosilicate glass (0.7 mm thickness) was heated to 200 ° C (measured by contact thermocouple on the surface of the substrate) on a nickel heating block. A gas mixture of 0.45% mol of Et2Zn · TMPDA (TMPDA = N, N, N ', N'-tetramethyl-1,3-propanediamine) and 0.0072% mol of Et2Al (acac) in 30 l / min of nitrogen vehicle gas at a temperature of 180 ° C was introduced through the primary chemical mouth of the coating nozzle. In a separate feeder, a mixture of 2.73% mol of water vapor (evaporated in vaporizer 1) and 1.59% mol of hexafluoropropene was introduced into the inner tube of the liner in 2.2 l / min of nitrogen gas vehicle.

The internal feeding tube was adjusted in such a way that the length of the mixing zone was 15 cm. The nitrogen gas vehicle flows were chosen such that the speeds of the two feeders were approximately equal. Under these conditions, the velocity at the outlet of the nozzle of the casing was approximately 100 cm / s, which correlates with a mixing time of the reactant of approximately 150 ms.

The substrate was pre-dosed for 5 seconds with the water vapor / hexafluoropropene mixture immediately before starting the flow of the Zn and Al precursor to the substrate. The deposition rate varied between 35 nm / s and 42 nm / s, which results in films with a thickness of 850-1000 nm. The resistance of the sheet was measured to be 50-55 ohm / sq and the resistivity of the film was 5-10-3 ohm · cm.

Example 19

Borosilicate glass (0.7 mm thickness) was heated to 200 ° C (measured by contact thermocouple on the surface of the substrate) on a nickel heating block. A mixture of 0.059% mol gas of Et2Zn · TMPDA (TMPDA = N, N, N ', N'-tetramethyl-1,3-propanediamine) and 0.0055% mol of Et2Al in 30 l / min of vehicle vehicle gas nitrogen at a temperature of 180 ° C was introduced through the primary chemical mouth of the coating nozzle. In a separate feeder, a mixture of 0.78% mol of 2-butanol gas (containing 5% mol of H2O) and 0.81% mol of hexafluoropropylene was introduced into the inner tube of the liner in 2.2 l / min of nitrogen gas vehicle.

The internal feeding tube was adjusted in such a way that the length of the mixing zone was 15 cm. The nitrogen gas vehicle flows were chosen such that the speeds of the two feeders were approximately equal. Under these conditions, the velocity at the outlet of the nozzle of the casing was approximately 100 cm / s, which correlates with a mixing time of the reactant of approximately 150 ms.

The deposition rate was 8.5 nm / s, which results in films with a thickness of 380 nm. The resistance of the sheet was measured to be 51 ohm / sq and the resistivity of the film was 2-10-3 ohm · cm.

Example 20

Borosilicate glass (0.7 mm thickness) was heated to 200 ° C (measured by contact thermocouple on the surface of the substrate) on a nickel heating block. A mixture of 0.059% mol gas of Et2Zn · TMPDA (TMPDA = N, N, N ', N'-tetramethyl-1,3-propanediamine) and 0.011% mol of Et2Al in 30 l / min of nitrogen vehicle gas at a temperature of 180 ° C was introduced through the primary chemical mouth of the coating nozzle. In a separate feeder, a mixture of 0.90% mol of 2-butanol gas (containing 20% ​​mol of H2O) and 0.81% mol of hexafluoropropene was introduced into the inner tube of the liner in 2.2 l / min of nitrogen gas vehicle.

The internal feeding tube was adjusted in such a way that the length of the mixing zone was 15 cm. The nitrogen gas vehicle flows were chosen such that the speeds of the two feeders were approximately equal. Under these conditions, the velocity at the outlet of the nozzle of the casing was approximately 100 cm / s, which correlates with a mixing time of the reactant of approximately 150 ms.

The deposition rate was 9.5 nm / s, which results in films with a thickness of 420 nm. The resistance of the sheet was measured to be 47 ohm / sq and the resistivity of the film was 2-10-3 ohm · cm.

As you can see from the results of examples 18-20, the use of water in combination with a dopant that

5 It contains Al and a dopant containing F (eg 18) provided high coating growth rates, but the strength of the sheet and the resistivity of the film was somewhat higher than that of examples 19 and 20. On the contrary, Examples 19 and 20 showed lower growth rates and desirable lower film resistivities using an alcohol / water mixture as an oxygen-containing compound.

Example 21

10 Borosilicate glass (0.7 mm thickness) was heated to approximately 200 ° C on a nickel heating block. A mixture of 0.26% mol of Me2Zn · TMPDA (TMPDA = N, N, N ', N'-tetramethyl-1,3-propanediamine) in 10 l / min of nitrogen vehicle gas at a temperature of 170 ° C is introduced through the primary chemical mouth of the coating nozzle. The doping precursor, Me2Ga (acac), was added to the primary feed stream through a stainless steel bubbler (16 ° C) using a vehicle

fifteen nitrogen gas at 30 sccm. In a secondary feeder, 1.66% mol of water vapor in 5 l / min of the nitrogen vehicle gas at a temperature of 170 ° C was introduced through the coating nozzle as illustrated in the Figure. The two precursor feeders were combined in a mixing chamber inside the coating nozzle and were directed towards the surface of the heated glass substrate. The films grew on a stationary substrate for 45 seconds.

twenty The deposition rate was 16 nm / s, which results in films with a thickness of 730 nm. The resistivity of the film was measured as 3.2-10-2 ohm · cm. The measurement of the Hall effect revealed a vehicle concentration of 3.5 x 1019 cm-3 and a mobility of 5.7 cm2 / Vs

The dynamic deposition system of Example 21 using water and a gallium dopant produced ZnO films with commercially viable thicknesses and low film resistivity.

25 Although the present invention has been described with respect to several specific examples and embodiments, it should be understood that the invention is not limited thereto and that it can be practiced variably within the scope of the following claims.