Low Resistivity Nitrogen-Doped Zinc Telluride and Methods for Forming the Same
Embodiments provided herein describe methods for forming nitrogen-doped zinc telluride, such as for use in photovoltaic devices. The zinc telluride layer is formed using physical vapor deposition (PVD) at a processing temperature of between about 100° C. and about 450° C. in a gaseous environment that includes between about 3% and about 10% by volume of nitrogen gas.
1 . A method for forming a photovoltaic device, the method comprising:
providing a transparent substrate;
forming a light-absorbing layer above the transparent substrate; and
forming a nitrogen-doped zinc telluride layer above the light-absorbing layer, wherein the nitrogen-doped zinc telluride layer is formed using physical vapor deposition (PVD) in a gaseous environment comprising between about 3% and about 10% by volume of nitrogen gas.
2 . The method of claim 1 , wherein the light-absorbing layer comprises cadmium telluride.
3 . The method of claim 2 , wherein the PVD processing temperature is between about 200° C. and about 400° C.
4 . The method of claim 3 , wherein the PVD processing temperature is between about 250° C. and about 375° C.
5 . The method of claim 2 , wherein the gaseous environment comprises between about 3% and about 9% by volume of nitrogen gas.
6 . The method of claim 5 , wherein the gaseous environment comprises between about 3% and about 8% by volume of nitrogen gas.
7 . The method of claim 2 , wherein the nitrogen-doped zinc telluride layer forms a back contact, and further comprising forming a front contact above the transparent substrate, the front contact comprising a transparent conductive oxide, wherein the light-absorbing layer is formed above the front contact.
8 . The method of claim 7 , wherein the transparent conductive oxide comprises indium-tin oxide.
9 . The method of claim 8 , further comprising forming a window layer above the front contact, the window layer comprising cadmium sulfide, wherein the light-absorbing layer is formed above window layer.
10 . The method of claim 9 , wherein the transparent substrate comprises glass.
11 . A method for forming a photovoltaic device, the method comprising:
providing a transparent substrate;
forming a front contact above the transparent substrate, wherein the front contact comprises a transparent conductive oxide;
forming a light-absorbing layer above the front contact, wherein the light absorbing layer comprises cadmium telluride; and
forming a back contact above the light-absorbing layer, the back contact comprising nitrogen-doped zinc telluride, wherein the nitrogen-doped zinc telluride is formed using physical vapor deposition (PVD) at a processing temperature of between about 100° C. and about 450° C. in a gaseous environment comprising between about 3% and about 10% by volume of nitrogen gas.
12 . The method of claim 11 , wherein the PVD processing temperature is between about 200° C. and about 400° C.
13 . The method of claim 12 , wherein the PVD processing temperature is between about 250° C. and about 375° C.
14 . The method of claim 11 , wherein the gaseous environment comprises between about 3% and about 9 % by volume of nitrogen gas.
15 . The method of claim 14 , wherein the gaseous environment comprises between about 3% and about 8% by volume of nitrogen gas.
16 . A method for forming a photovoltaic device, the method comprising:
providing a glass substrate;
forming a front contact above the glass substrate, wherein the front contact comprises a transparent conductive oxide;
forming a light-absorbing layer above the front contact, wherein the light absorbing layer comprises cadmium telluride; and
forming a back contact above the light-absorbing layer, the back contact comprising nitrogen-doped zinc telluride, wherein the nitrogen-doped zinc telluride is formed using physical vapor deposition (PVD) at a processing temperature of between about 100° C. and about 450° C. in a gaseous environment comprises between about 3% and about 10% by volume of nitrogen gas.
17 . The method of claim 16 , wherein the PVD processing temperature is between about 200° C. and about 400° C.
18 . The method of claim 17 , wherein the gaseous environment comprises between about 3% and about 9% by volume of nitrogen gas.
19 . The method of claim 18 , wherein the PVD processing temperature is between about 250° C. and about 375° C.
20 . The method of claim 19 , wherein the gaseous environment comprises between about 3% and about 8% by volume of nitrogen gas.