Method for manufacturing multijunction photoelectric conversion device
A method for manufacturing a multi-junction photoelectric conversion device includes forming a first electrode on a first photoelectric conversion unit including a first semiconductor layer as a photoelectric conversion layer, the first electrode including a plurality of patterned regions separated from one another by separation grooves; and eliminating a leakage existing in the first semiconductor layer by applying a reverse bias voltage between one of the patterned regions of the first electrode and a second photoelectric conversion unit comprising a second semiconductor layer as a photoelectric conversion layer. The application of the reverse bias voltage is performed while irradiating the second photoelectric conversion unit with light, generating a photocurrent in the second photoelectric conversion unit that is larger than a photocurrent in the first photoelectric conversion unit.
1. A method for manufacturing a multi-junction photoelectric conversion device, the method comprising:
forming a first electrode on a first photoelectric conversion unit comprising a first semiconductor layer as a photoelectric conversion layer, the first electrode comprising a plurality of patterned regions separated from one another by separation grooves; and
eliminating a leakage existing in the first semiconductor layer by applying a reverse bias voltage between one of the patterned regions of the first electrode and a second photoelectric conversion unit comprising a second semiconductor layer as a photoelectric conversion layer,
wherein the application of the reverse bias voltage is performed while irradiating the second photoelectric conversion unit with light, generating a photocurrent in the second photoelectric conversion unit that is larger than a photocurrent in the first photoelectric conversion unit,
wherein the photoelectric conversion device comprises, in the following order:
the first electrode;
the first photoelectric conversion unit; and
the second photoelectric conversion unit,
wherein the first semiconductor layer is a thin film, and
wherein the second photoelectric conversion unit is connected to the first photoelectric conversion unit in series.
2. The method according to claim 1 , wherein the first semiconductor layer has a band gap that is wider than a band gap of the second semiconductor layer, and the photoelectric conversion device has a light-receiving surface on the first electrode side.
3. The method according to claim 1 , wherein the first electrode is a transparent electrode.
4. The method according to claim 1 , wherein the second semiconductor layer is a crystalline semiconductor substrate.
5. The method according to claim 1 , wherein the first semiconductor layer contains a photosensitive material having a perovskite-type crystal structure.
6. The method according to claim 1 , wherein the first electrode is formed by depositing an electrode layer on the first photoelectric conversion unit, followed by forming the separation grooves by irradiating the electrode layer with laser light.
7. The method according to claim 1 , wherein the first electrode is formed by depositing an electrode layer on the first photoelectric conversion unit, followed by forming the separation grooves by pattern etching the electrode layer.
8. The method according to claim 1 , wherein the first electrode is formed by depositing an electrode layer while the first photoelectric conversion unit is covered with a mask, forming the separation grooves in a region covered with the mask.
9. The method according to claim 1 , wherein a metal electrode is disposed in each of the patterned regions of the first electrode, and the metal electrode is electrically connected to a power supply to apply the reverse bias voltage.
10. The method according to claim 1 , further comprising electrically connecting the plurality of the patterned regions of the first electrode after eliminating the leakage.
11. The method according to claim 10 , wherein the separation groove is filled with an electroconductive material to electrically connect the plurality of the patterned regions of the first electrode.
12. The method according to claim 11 , further comprising, after the separation groove is filled with the electroconductive material, eliminating a leakage in the first semiconductor layer remaining in a separation groove-formed region by applying a reverse bias voltage between the electroconductive material filled into the separation groove and the second photoelectric conversion unit while irradiating the second photoelectric conversion unit with light, generating a photocurrent in the second photoelectric conversion unit that is larger than a photocurrent in the first photoelectric conversion unit.
13. The method according to claim 11 , further comprising, after the separation groove is filled with the electroconductive material, disposing the electroconductive material on the first electrode over the plurality of the patterned regions of the first electrode.
14. The method according to claim 10 , wherein the plurality of the patterned regions of the first electrode are electrically connected by disposing the electroconductive material on the first electrode over the plurality of the patterned regions of the first electrode.
15. The method according to claim 14 , wherein the separation groove is filled with an insulating material before the electroconductive material is disposed.