Patent ID: 9214581
Filing Date: 2015-12-15
Classification: H01L,Y02E,Y02P

Abstract:
1. An infrared photodetector comprising: a substrate formed of a substrate material having a substrate lattice constant; an infrared barrier detector structure comprising at least one absorber superlattice and at least one contact layer, and at least one unipolar barrier layer disposed between said at least one absorber layer superlattice and said contact layer, the detector structure having a detector lattice constant, wherein the substrate and detector lattice constants are mismatched such that the substrate and detector cannot be strain balanced; and a transitional structure disposed between the substrate and the detector structure, wherein the transitional structure is formed from at least one of an interfacial misfit array, a compositionally graded metamorphic buffer layer, and a superlattice metamorphic buffer layer; wherein the transitional structure further comprises a template layer formed adjacent the detector structure, wherein the template layer is formed from a material having a lattice constant strain balanced to the lattice constant of the detector structure; and wherein the transitional structure forms a virtual substrate having a lattice constant that is pseudomorphic to the detector lattice constant.