Semitransparent chalcogen solar cell

A method of forming a solar cell, the method comprising the steps of:

• forming a first transparent contact on a substrate, wherein the first transparent contact is formed as a single layer disposed on, and fully covering, the substrate;
• depositing an n-type layer directly on the first transparent contact, wherein the n-type layer comprises a material selected from the group consisting of:
• cadmium sulfide, a cadmium-zinc-sulfur material, indium sulfide, zinc oxysulfide, aluminum oxide, zinc magnesium oxide, and combinations thereof;
• depositing a p-type chalcogen absorber layer on the n-type layer, wherein a p-n junction is formed between the p-type chalcogen absorber layer and the n-type layer, the p-type chalcogen absorbing layer comprising only sulfur, selenium, and/or tellurium;
• depositing a protective interlayer onto the p-type chalcogen absorber layer by evaporation, wherein the protective interlayer fully covers the p-type chalcogen absorber layer, wherein the protective interlayer comprises a material having a workfunction of greater than about 5.2 electron volts, and wherein the protective interlayer comprises molybdenum trioxide;
• and
• forming a second transparent contact directly on the protective interlayer with the protective interlayer tuning a workfunction of the second transparent contact, wherein the protective interlayer being disposed between the p-type chalcogen absorber layer and the second transparent contact serves to protect the p-n junction during the forming of the second transparent contact.