ALD processed MgZnO buffer layers for Cu(In,Ga)S2 solar cells

CIGS thin film heterostructures are fabricated by low cost, solution based processes. While a standard process includes a CdS buffer layer, MgZnO provides a more environmentally friendly material. In this study, MgZnO thin films were deposited by atomic layer deposition and their physical properties were studied by changing various conditions including growth temperature, pressure, and doping ratio. CIGS photovoltaic devices with MgZnO buffer layers of varied properties were fabricated and compared with those with CdS buffer layers and without any buffer layer.