Double layered transparent conductive oxide for reduced Schottky barrier in photovoltaic devices

A method for fabricating a photovoltaic device, comprising:

• forming a double layer transparent conductive oxide on a transparent substrate including:
• sputtering on a doped electrode layer on the substrate using a first target source;
• switching to a second target source in-situ, wherein the photovoltaic device being fabricated remains in a same processing chamber for formation of the entire double layer;
• and
• sputtering on a buffer layer comprising an oppositely doped form of a same material as the doped electrode layer on the doped electrode layer using the second target source, the buffer layer including a different doping concentration than the doped electrode layer;
• and
• forming a light-absorbing semiconductor structure including a p-type semiconductor layer on the buffer layer, an intrinsic layer and an n-type semiconductor layer.

A method for fabricating a photovoltaic device, comprising:

• forming a double layer transparent conductive oxide on a transparent substrate including:
• depositing a doped electrode layer on the substrate using a low pressure chemical vapor deposition (LPCVD) process;
• and
• forming a buffer layer comprising an oppositely doped form of a same material as the doped electrode layer on the doped electrode layer using the LPCVD process by reducing dopant concentration to zero, the buffer layer including a different doping concentration than the doped electrode layer;
• and
• forming a light-absorbing semiconductor structure including a p-type semiconductor layer on the buffer layer, an intrinsic layer and an n-type semiconductor layer.