Patent ID: 8735202
Filing Date: 2014-05-27
Classification: H01L,Y02E

Abstract:
1. A method of fabricating a solar photovoltaic converter comprising: depositing a first subcell on a substrate by epitaxial growth of a semiconductor material that has a lattice constant matched to the substrate and that has a first bandgap which is at least 1.2 eV; depositing a graded layer over the first subcell by epitaxially growing a compositionally graded semiconductor material that begins with a first lattice constant that is matched to the substrate and ends with a second lattice constant that is higher than said first lattice constant; and depositing a second subcell over the graded layer by epitaxially growing a semiconductor material that has a lattice constant matched to the graded layer, but lattice mismatched to substrate, and that has a second bandgap which is lower than the first bandgap and not higher than 1.2 eV.