A photovoltaic solar cell comprises a thin silicon or silicon dioxide substrate. The photovoltaic solar cell also comprises a first layer over said substrate. The first layer comprises tellurium (Te) and one or more of cadmium (Cd) and zinc (Zn). Additionally, the first layer is doped p-type. The photovoltaic solar cell also comprises a second layer adjacent to the first layer. The second layer comprises Te and two or more of Cd, Zn, magnesium (mg), and selenium (Se). The photovoltaic solar cell also comprises a third layer adjacent to the second layer. The third layer comprises Zn and one or more of Cd, Se, and Sulphur (S). The third layer is doped n-type.

A photovoltaic solar cell comprises a thin silicon or silicon dioxide substrate. The photovoltaic solar cell also comprises a first layer over said substrate. The first layer comprises tellurium (Te) and one or more of cadmium (Cd) and zinc (Zn). Additionally, the first layer is doped p-type. The photovoltaic solar cell also comprises a second layer adjacent to the first layer. The second layer comprises Te and two or more of Cd, Zn, magnesium (mg), and selenium (Se). The photovoltaic solar cell also comprises a third layer adjacent to the second layer. The third layer comprises Zn and one or more of Cd, Se, and Sulphur (S). The third layer is doped n-type.

A photovoltaic device includes a substrate structure and a p-type semiconductor absorber layer. A photovoltaic device may include a CdSeTe layer. A process for manufacturing a photovoltaic device includes forming a CdSeTe layer over a substrate. The process includes forming a p-type cadmium selenide telluride absorber layer.

A photovoltaic device includes a substrate structure and a p-type semiconductor absorber layer. A photovoltaic device may include a CdSeTe layer. A process for manufacturing a photovoltaic device includes forming a CdSeTe layer over a substrate. The process includes forming a p-type cadmium selenide telluride absorber layer.

The invention discloses nanocrystalline (NC) FeS.sub.2 thin films as the back contact for CdTe solar cells. In one example, the FeS.sub.2 NC layer is prepared from a solution directly on the CdTe surface using spin-casting and chemical treatment at ambient temperature and pressure, without a thermal treatment step. Solar cells prepared by applying the NC FeS.sub.2 back contact onto CdTe yield efficiencies of about 95% to 100% that of standard Cu/Au back contact devices. In another example, FeS.sub.2 is interposed between Cu and Au to form a Cu/FeS.sub.2 NC/Au back contact configuration yielding an efficiency improvement of 5 to 9 percent higher than standard Cu/Au devices.

The invention discloses nanocrystalline (NC) FeS.sub.2 thin films as the back contact for CdTe solar cells. In one example, the FeS.sub.2 NC layer is prepared from a solution directly on the CdTe surface using spin-casting and chemical treatment at ambient temperature and pressure, without a thermal treatment step. Solar cells prepared by applying the NC FeS.sub.2 back contact onto CdTe yield efficiencies of about 95% to 100% that of standard Cu/Au back contact devices. In another example, FeS.sub.2 is interposed between Cu and Au to form a Cu/FeS.sub.2 NC/Au back contact configuration yielding an efficiency improvement of 5 to 9 percent higher than standard Cu/Au devices.

A photovoltaic cell can include a dopant in contact with a semiconductor layer.

A photovoltaic cell can include a dopant in contact with a semiconductor layer.

A photovoltaic device includes an electron blocking layer (EBL) and an absorber layer. The EBL is positioned between the absorber layer and a back contact layer. A material of the EBL is a cadmium zinc telluride Cd.sub.(1-y)Zn.sub.(y)Te, and a material of the absorber layer is a cadmium telluride selenide CdTe.sub.(1-x)Se.sub.(x) producing a lattice mismatch between the materials of the EBL and between the materials of the absorber of less than about two tenths of a percent when x?y and has a value less than about 0.4.

A photovoltaic device includes an electron blocking layer (EBL) and an absorber layer. The EBL is positioned between the absorber layer and a back contact layer. A material of the EBL is a cadmium zinc telluride Cd.sub.(1-y)Zn.sub.(y)Te, and a material of the absorber layer is a cadmium telluride selenide CdTe.sub.(1-x)Se.sub.(x) producing a lattice mismatch between the materials of the EBL and between the materials of the absorber of less than about two tenths of a percent when x?y and has a value less than about 0.4.