Photovoltaic device including a P-N junction and method of manufacturing
A photovoltaic device includes a substrate structure and a p-type semiconductor absorber layer, the substrate structure including a CdSSe layer. A photovoltaic device may alternatively include a CdSeTe layer. A process for manufacturing a photovoltaic device includes forming a CdSSe layer over a substrate by at least one of sputtering, evaporation deposition, CVD, chemical bath deposition process, and vapor transport deposition process. The process includes forming a p-type absorber layer above the CdSSe layer.
1. A process for manufacturing a photovoltaic structure comprising:
forming a cadmium sulphoselenide layer over a substrate structure; and
forming a p-type absorber layer over the cadmium sulphoselenide layer, wherein the p-type absorber layer comprises cadmium and tellurium;
wherein the method comprises depositing a cadmium sulphotelluride interfacial layer over the cadmium sulphoselenide layer and then forming the p-type absorber layer over the cadmium sulphotelluride layer;
wherein the cadmium sulphoselenide layer is formed by one of: closed space sublimation, sputtering, vapor transport deposition, atomic layer deposition, and chemical bath deposition;
the process further comprising a step of annealing at an elevated temperature to create a compound region containing cadmium, sulfur, tellurium, and selenium in CdS x Te y Se z where 0<x<1, 0<y<1, and 0<z<1 at %.
2. A process for manufacturing as in claim 1 , further comprising the first step of depositing an n-type semiconductor window layer over a substrate structure and then performing the step of forming a cadmium sulphoselenide layer over the substrate structure.
3. A process for manufacturing as in claim 1 , where the step of forming the cadmium sulphoselenide layer includes co-evaporating blended cadmium sulfide powder and cadmium selenide powder.
4. A process for manufacturing as in claim 1 , where the step of forming the cadmium sulphoselenide layer includes evaporating pre-alloyed cadmium sulphoselenide powder.
5. A process for manufacturing a photovoltaic structure comprising:
forming a cadmium sulphoselenide layer over a substrate structure; and
forming a p-type absorber layer over the cadmium sulphoselenide layer;
wherein the cadmium sulphoselenide layer is formed by one of: closed space sublimation, sputtering, vapor transport deposition, atomic layer deposition, and chemical bath deposition; and
where the step of forming the cadmium sulphoselenide layer includes:
forming a cadmium sulfide layer,
forming a cadmium selenide layer, and
annealing the cadmium sulfide and cadmium selenide layers to form cadmium sulphoselenide.
6. A process for manufacturing as in claim 5 where the step of annealing the cadmium sulfide and cadmium selenide layers occurs concurrently with the step of forming a p-type absorber layer over the cadmium selenide layer.