Silicon heterojunction photovoltaic device with non-crystalline wide band gap emitter

摘要

A photovoltaic device including a single junction solar cell provided by an absorption layer 10 of a type IV semiconductor material having a first conductivity, and an emitter layer 20 of a type III-V semiconductor material having a second conductivity, wherein the type III-V semiconductor material is non-crystalline and has a thickness that is no greater than 50 nm. Wherein, the type III-V semiconductor material may be amorphous, nano-crystalline or micro-crystalline. Also disclosed is a method of forming a photovoltaic device as above. The type IV semiconductor material may be silicon (Si), germanium (Ge), silicon-germanium (SiGe) alloy, silicon doped with carbon (Si:C) or a combination thereof. The type III-V material may be any semiconductive III-V material, including binary, tertiary and quaternary materials but is more preferably gallium nitride (GaN), indium gallium nitride (InGaN), gallium phosphide (GaP), indium phosphide (InP), gallium phosphide nitride (GaPN) or combinations thereof. The emitter layer 20 may be in direct contact with the absorption layer 10 or a buffer layer of type III-V semiconductor material may be provided between the absorption layer 10 and emitter layer 20.