Patent ID: 8653360
Filing Date: 2014-02-18
Classification: H01L,Y02E

Abstract:
1. A photovoltaic device comprising a stack, from top to bottom, of a first intrinsic compositionally-graded semiconductor layer including a first compositionally-graded alloy of silicon and germanium, an intrinsic semiconductor material layer having a thickness ranging from 10 nm to 400 nm and consisting of germanium formed directly on said first intrinsic compositionally-graded semiconductor layer, and a second intrinsic compositionally-graded semiconductor layer including a second compositionally-graded alloy of silicon and germanium formed directly on said intrinsic semiconductor material layer, wherein an atomic concentration of germanium decreases with distance from an interface between said intrinsic semiconductor layer and both said first intrinsic compositionally-graded alloy and said second intrinsic compositionally-graded alloy, and an atomic concentration of silicon increases with distance from the interface between said intrinsic semiconductor layer and both said first intrinsic compositionally-graded alloy and said second intrinsic compositionally-graded alloy.