Copper delafossite transparent P-type semiconductor thin film devices
Methods for fabrication of copper delafossite materials include a low temperature sol-gel process for synthesizing CuBO 2 powders, and a pulsed laser deposition (PLD) process for forming thin films of CuBO 2 , using targets made of the CuBO 2 powders. The CuBO 2 thin films are optically transparent p-type semiconductor oxide thin films. Devices with CuBO 2 thin films include p-type transparent thin film transistors (TTFT) comprising thin film CuBO 2 as a channel layer and thin film solar cells with CuBO 2 p-layers. Solid state dye sensitized solar cells (SS-DSSC) comprising CuBO 2 in various forms, including “core-shell” and “nano-couple” particles, and methods of manufacture, are also described.
1. A thin film solar cell comprising:
a substrate;
a copper boron oxide p-layer over said substrate, said copper boron oxide p-layer comprising an optically transparent p-type semiconductor, wherein said optically transparent p-type semiconductor is CuBO 2 copper delafossite;
a thin film of n-type transparent conducting oxide between said substrate and said copper boron oxide p-layer;
an amorphous silicon absorber layer over said copper boron oxide p-layer;
a n-type amorphous silicon layer over said amorphous silicon absorber layer; and
a back contact layer over said n-type amorphous silicon layer.
2. The thin film solar cell as in claim 1 , wherein said copper boron oxide p-layer is a thin film, said thin film having a thickness in the range of 8 to 100 nanometers.
3. The thin film solar cell as in claim 1 , wherein said substrate comprises glass.
4. A thin film solar cell comprising:
a substrate;
a transparent n-layer over said substrate; and
a p-layer between said substrate and said transparent n-layer;
wherein said p-layer comprises an absorber material and a copper boron oxide layer, said copper boron oxide layer comprising an optically transparent p-type semiconductor, wherein said optically transparent p-type semiconductor is CuBO 2 copper delafossite.
5. The thin film solar cell as in claim 4 , wherein said absorber material comprises copper indium gallium selenide.
6. The thin film solar cell as in claim 4 , wherein said copper boron oxide p-layer is a thin film, said thin film having a thickness of 20 nanometers.
7. The thin film solar cell as in claim 4 , wherein said copper boron oxide p-layer is between said absorber material and said transparent n-layer.
8. A thin film solar cell comprising:
a substrate; and
a p-layer over said substrate;
wherein said p-layer comprises a copper boron oxide p-layer and a second layer of p-type material, said copper boron oxide p-layer comprising an optically transparent p-type semiconductor, wherein said optically transparent p-type semiconductor is CuBO 2 copper delafossite, and wherein said second layer of p-type material is selected from the group consisting of a layer of p-type amorphous silicon, a layer of p-type microcrystalline silicon and a layer of p-type microcrystalline silicon carbide.
9. The thin film solar cell as in claim 8 , wherein said second layer of p-type material is said layer of p-type amorphous silicon.
10. The thin film solar cell as in claim 8 , wherein said second layer of p-type material is said layer of p-type microcrystalline silicon.
11. The thin film solar cell as in claim 8 , wherein said second layer of p-type material is said layer of p-type microcrystalline silicon carbide.
12. A thin film solar cell comprising:
a substrate;
a transparent conductive layer over said substrate;
a first copper boron oxide p-layer over said transparent conductive layer, said first copper boron oxide p-layer comprising an optically transparent p-type semiconductor, wherein said optically transparent p-type semiconductor is CuBO 2 copper delafossite;
a first layer of intrinsic semiconductor over said first copper boron oxide p-layer;
a first n-type semiconductor layer over said first layer of intrinsic semiconductor;
a second copper boron oxide p-layer over said first n-type semiconductor layer, said second copper boron oxide p-layer comprising an optically transparent p-type semiconductor, wherein said optically transparent p-type semiconductor is CuBO 2 copper delafossite;
a second layer of intrinsic semiconductor over said second copper boron oxide p-layer;
a second n-type semiconductor layer over said second layer of intrinsic semiconductor; and
a back contact layer over said second n-type semiconductor layer.
13. The thin film solar cell as in claim 12 , wherein said substrate comprises glass.
14. The thin film solar cell as in claim 12 , wherein said first and second copper boron oxide p-layers have thicknesses in the range of 8 to 100 nanometers.
15. The thin film solar cell as in claim 12 , wherein said first layer of intrinsic semiconductor and said second layer of intrinsic semiconductor are comprised of different materials.
16. The thin film solar cell as in claim 15 , wherein said first layer of intrinsic semiconductor comprises amorphous silicon and said second layer of intrinsic semiconductor comprises microcrystalline silicon.