Optoelectric element

Optoelectronics

With reference to the specific embodiments described below, these and other aspects of the present invention will be clarified and become obvious.

Figure 1 shows an example of one of the steps of the method according to the present invention, and

Figure 2 shows an example of a photovoltaic element according to the present invention.

The present invention relates to a photoelectric element containing a semiconductor substrate. This semiconductor-based system is provided on a substrate formed of an electrically insulating material and covered with a light-emitting layer to convert electromagnetic radiation in the first wavelength range generated by the semiconductor substrate. Into visible light of different wavelengths.

The present invention also relates to a method of covering a photovoltaic element with a light-emitting layer.

The optoelectronic element mentioned above is disclosed in U.S. Patent No. 5,813,752. In the known optoelectronic element, the semiconductor base and the substrate form a part of the light-emitting diode. The light-emitting layer converts the ultraviolet light and blue light generated by the light-emitting diode into visible light in different wavelength ranges. In this way, these light-emitting diodes can be made suitable for different applications requiring different colors of visible light. However, the problem is that it is usually difficult to obtain an easily controllable close contact layer and a substantially uniform thickness method to apply the light-emitting layer to the optoelectronic device.

Therefore, the object of the present invention is to provide a photoelectric element with a uniform thickness of a close contact light-emitting layer in a relatively simple manner.

In order to achieve this objective, the photoelectric element described in the opening paragraph according to the present invention is characterized in that the conductive layer is located between the substrate and the light-emitting layer, and during the operation of the photoelectric element, the selected conductivity X is such that the conductive layer passes through The current is up to 5% of the current through the semiconductor element.

In fact, the conductive layer is usually connected to the different electrodes of the photovoltaic element. The conductivity of this layer is chosen so low that this layer does not cause short circuits between the electrodes of the optoelectronic element, and hardly adversely affects the function of the optoelectronic element. Surprisingly, at the same time, it has been found that the conductivity is high enough that the luminescent material can be deposited by electrophoresis from an appropriately selected slurry, and in this process, the conductive layer is used as one of the electrodes. In this way, it is easy to provide a uniform thickness and a close contact layer forming part of the optoelectronic element, and the optoelectronic properties of the optoelectronic element will not be adversely affected by this conductive layer.

It has been found that according to the optoelectronic device of the present invention, during the operation of the optoelectronic device, the current passing through the conductive layer can be at most 10% of the current passing through the semiconductor device.

If the conductive layer is transparent to the electromagnetic radiation generated by the semiconductor element, the photovoltaic element according to the present invention has a relatively high efficiency.

The desired result is achieved by using the specific embodiment of the photoelectric element according to the present invention, in which the conductive layer includes a transparent oxide, more specifically, the oxide is selected from the group consisting of indium tin oxide, antimony tin oxide and tin oxide Family.

The desired results are also achieved using specific embodiments of the photovoltaic element according to the present invention, in which the semiconductor matrix forms part of the light-emitting diode.

In the method mentioned in the second paragraph of this description, in order to cover an optoelectronic element containing a semiconductor substrate provided on an electrically insulating substrate, according to the present invention, the method includes a step in which the substrate is covered with a conductive layer, and then At least the substrate is brought into contact with the suspension of the luminescent material deposited on the surface of the conductive layer by electrophoresis. The conductivity X of this conductive layer is higher than that of the suspension, but lower than that of the semiconductor element. The conductive layer is used as the first electrode , The second electrode exists in the suspension and maintains the potential difference between the electrodes.

It has been found that this method is very suitable for covering optoelectronic devices containing light-emitting diodes.

It has also been found that the method according to the present invention can be advantageously and conveniently applied to optoelectronic components connected to a carrier, and this carrier also provides many optoelectronic components so that all these optoelectronic components can simultaneously cover a light-emitting layer.

Schematic description

With reference to the specific embodiments described below, these and other aspects of the present invention will be clarified and become obvious.

Figure 1 shows an example of one of the steps of the method according to the present invention, and

Figure 2 shows an example of a photovoltaic element according to the present invention.

Detailed description of the invention:

In Figure 1, LF represents a conductive material carrier. A represents a heat sink (heat sink), which is provided in the hole of the carrier board LF and is made of metal. On the heat sink A, a submount B composed of a silicon wafer covered with a layer of aluminum is provided. The end of the sub-base body B is connected to each bonding wire, and each bonding wire is connected to the carrier board LF. D represents a light-emitting diode containing a substrate. This substrate is made of an electrically insulating ceramic material, on which some epitaxial layers containing semiconductor materials are provided. These epitaxial layers together form the semiconductor substrate. C represents a solder ball that forms electrical contact between the light-emitting diode D and the sub-substrate B. ST stands for droplets of suspension S of luminescent material. This droplet ST is in contact with the outer parts of the heat sink A, the sub-substrate B, the contact body C, and the light emitting diode D. The outer parts of the heat sink A, the sub-substrate B, the contact body C and the light-emitting diode D in contact with the suspension provide a conductive layer EL, the conductivity of which is selected to be higher than that of the suspension, but lower than that of the semiconductor substrate. This suspension system uses a pump to transfer in the direction indicated by the arrow, so that the part of the suspension close to the surface of the light-emitting diode D is continuously updated. The cathode of the voltage source Vg is connected to the conductive layer via the carrier LF and the bonding wire BD, so that this layer forms a cathode in contact with the suspension. The anode of the voltage source Vg is connected to the electrode E located in the suspension. Under the influence of the voltage V generated by the voltage source, the luminescent material layer is deposited on the surface of the conductive layer by electrophoresis.

In a practical embodiment of the steps of the method shown in FIG. 1, the conductive layer is made of antimony tin oxide and has a thickness of about 50 nanometers. This conductive layer is provided by wetting the surface of the photovoltaic element with a solution of antimony tin oxide. This photoelectric element contains a sapphire substrate, on which is provided a semiconductor substrate containing an epitaxial layer of aluminum gallium indium nitride (AlGaInN). If current flows through this semiconductor substrate, blue light is generated. The suspension used contains strontium phosphate. The conductivity of this suspension is about 300 pS/meter. It has been found that under the influence of a voltage of 200 volts, the surface of the light-emitting diode D is electrophoretically covered with a light-emitting layer of about 50 microns within 50 seconds.

In Fig. 2, the parts corresponding to the parts shown in Fig. 1 have the same reference numerals. The conductive layer EL covers a part of the outer surface of the heat sink A, the sub-base body B, the contact body C and the light emitting diode D. The conductive layer EL is then completely covered by a light-emitting layer LU. As a result, not only the surface of the light-emitting diode D that turns from the heat sink to one side is covered with a layer of luminescent material, but also the side that extends vertically there. In order to influence the direction of light generated by the light-emitting layer, a hemispherical substrate is provided on the light-emitting diode D. The hemispherical substrate provides a pair of visible light transparent screen walls E and a pair of visible light transparent fillers F. If a voltage is applied to the end of the welding wire contacting the carrier board LF, the light-emitting diode D generates electromagnetic radiation in the first wavelength range, and the light-emitting layer converts ultraviolet light into visible light in a different wavelength range. Due to the presence of the screen wall E and the transparent filler F, the light essentially flows out in the direction of the longitudinal axis of the photoelectric element.