Patent ID: 8253145

Claim:
A semiconductor device comprising: at least one active layer composed of a first compound; and at least one barrier layer composed of a second compound and disposed on at least one surface of the at least one active layer, wherein an energy band gap of the at least one barrier layer is wider than an energy band gap of the at least one active layer, wherein the first and/or second compounds are selected to strengthen an excitonic binding between an electron and a hole in the at least one active layer, wherein the second compound comprises CuFCl, CuBrF, CuFI, CuClBr, CuClI, CuBrI, AgFCl, AgFBr, AgFI, AgClBr, AgClI, AgBrI, AuFCl, AuFBr, AuFI, AuClBr, AuClI, AuBrI, CuFClBr, CuFClI, CuFBrI, CuIBrCl, AgFClBr, AgFClI, AgFBrI, AgClBrI, AuFClBr, AuFClI, AuFBrI, or AuClBrI.