Patent ID: 7671341
Filing Date: 2010-03-02
Classification: H01L

Abstract:
1. An electromagnetic radiation detector responsive to n discrete wavelength ranges, where n is odd and greater than or equal to 3, characterised as λ 0 -λ 1 , λ 1 -λ 2 , . . . , λ n−1 -λ n within a total wavelength range λ 0 -λ n where λ 0 <λ 1 <λ 2 < . . . λ n−1 <λ n , the detector comprising a plurality of layers of semiconductor material providing: a substrate substantially transparent to electromagnetic radiation within said wavelength range λ a first sequence of layers, each doped to provide a first type of electrical conductivity, and each having a different bandgap selected for absorbing radiation up to selected first wavelengths of λ a second sequence of layers, interspersed with layers of said first sequence, each doped to provide a second type of electrical conductivity, and each having a different bandgap selected for absorbing radiation up to selected second wavelengths of λ terminals electrically coupled to each layer in said first sequence of layers to apply a bias to said first and second sequence of layers to permit detection of radiation in selected ones of the wavelength ranges λ