Photoelectric conversion device with improved back reflection layer

• US 5,453,135 A
• Filed: 12/28/1993
• Issued: 09/26/1995
• Est. Priority Date: 12/28/1992
• Status: Expired due to Term

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Nakagawa, Katsumi, Toyama, Noboru, Yamashita, Toshihiro
• Primary Examiner(s): Weisstuch, Aaron
• Application Number:
  US08/174,011
• Time in Patent Office: 637 Days
• Field of Search: 136/256, 136/258 AM, 136/259, 136/249 TJ, 257/436, 257/458, 204/192.29
• US Class Current: 136/259
• CPC Class Codes: H01L 31/022483 composed of zinc oxide [ZnO]
• CPC Class Codes: H01L 31/0392 including thin films deposited on metallic or insulating substrates ; characterised by specific substrate materials or substrate features or by the presence of intermediate layers, e.g. barrier layers, on the substrate textured substrates H01L31/02366
• CPC Class Codes: H01L 31/056 the light-reflecting means being of the back surface reflector [BSR] type
• CPC Class Codes: H01L 31/076 Multiple junction or tandem solar cells
• CPC Class Codes: H01L 31/1884 Manufacture of transparent electrodes, e.g. TCO, ITO
• CPC Class Codes: Y02E 10/52 PV systems with concentrators
• CPC Class Codes: Y02E 10/548 Amorphous silicon PV cells

Abstract

A photoelectric conversion device comprising at least a metal layer, a transparent conductive layer disposed on said metal layer, and an active semiconductor layer disposed on said transparent conductive layer, characterized in that said transparent conductive layer comprises a layer having an uneven surface which is composed of a zinc oxide material having an X-ray diffraction pattern in which (a) the peak intensity of the (2,0,0) planes of ZnO₂ is 1/200 or less of (b) the peak intensity of the (0,0,2) planes of ZnO and (c) the peak intensity of the (1,0,1) planes of Zn is 1/200 or less of the peak intensity (b).

Claims

1. A photovoltaic conversion device comprising at least a metal layer, a transparent conductive layer disposed on said metal layer, and an active semiconductor layer disposed on said transparent conductive layer, characterized in that said transparent conductive layer comprises a layer having an uneven surface which is composed of a zinc oxide material Zn_1-x O_x (0<

x<

1) having an X-ray diffraction pattern in which (a) the peak intensity of the (2,0,0) planes of ZnO₂ is 1/200 or less of (b) the peak intensity of the (0,0,2) planes of ZnO and (c) the peak intensity of the (1,0,1) planes of Zn is 1/200 or less of the peak intensity (b).

2. A photoelectric conversion device according to claim 1, wherein the zinc oxide material contains ZnO as the main constituent and at least one of Zn and ZnO₂.

3. A photoelectric conversion device according to claim 2, wherein Zn is contained in the zinc oxide material in an amount in the range of 150 to 400 ppm.

4. A photoelectric conversion device according to claim 2, wherein ZnO₂ is contained in the zinc oxide material in an amount in the range of 250 to 600 ppm.

5. A photoelectric conversion device according to claim 1, wherein the active semiconductor layer comprises a silicon-containing non-single crystal semiconductor.

6. A photoelectric conversion device according to claim 1, wherein the metal layer is composed of a metal selected from the group consisting of Ag, Al, and Cu.

7. A photoelectric conversion device according to claim 1, wherein the transparent conductive layer has a polycrystalline structure.

8. A photoelectric conversion device according to claim 1, wherein the transparent conductive layer has a microcrystalline structure.

9. A photoelectric conversion device according to claim 1, wherein the zinc oxide material has a resistivity in the range of 1×

10^-5 to 1×

10² Ω

/cm².

10. A photoelectric conversion device according to claim 1, wherein the zinc oxide material contains a metal selected from the group consisting of Al and Cu.

11. A photoelectric conversion device according to claim 1, wherein the active semiconductor layer has a tandem structure.

12. A photoelectric conversion device according to claim 11, wherein the tandem structure is a stacked structure comprising a non-single crystal silicon semiconductor and a non-single crystal silicon-germanium semiconductor.

13. A photoelectric conversion device according to claim 1, wherein the uneven surface of the transparent conductive layer is provided with irregularities of 0.3 to 0.7 μ

m in terms of the mean pitch.

14. A photoelectric conversion device according to claim 1, wherein the active semiconductor layer comprises a compound semiconductor.

15. A photoelectric conversion device according to claim 14, wherein the compound semiconductor has a stacked structure comprising CIS/CdS.

16. A photoelectric conversion according to claim 1 which has a pin junction.

17. A photoelectric conversion according to claim 1 which has a pn junction.

18. A photoelectric conversion device according to claim 1, wherein the zinc oxide material is a zinc oxide material formed by a magnetron sputtering process wherein the formation of said zinc oxide material is conducted under conditions of maintaining the sputtering chamber pressure at 3 mTorr or below, maintaining the substrate at a temperature in the range of 150°

to 350°

C., and supplying O₂ gas or an oxygen-containing compound gas.

19. A photoelectric conversion device according to claim 1, wherein the zinc oxide material is a zinc oxide material formed by a reactive vacuum deposition process wherein the formation of said zinc oxide material is conducted under conditions of maintaining the vacuum chamber pressure at 0.5 mTorr or below, maintaining the substrate at a temperature in the range of 100°

to 250°

C., and supplying O₂ gas or an oxygen-containing compound gas.

20. A photoelectric conversion device according to claim 18 or 19, wherein the oxygen-containing compound gas is H₂ O, NO, NO₂, CO, CO₂, or CH₃ OH.