Exceptionally Narrow-Band Quantum Dot Infrared Photodetector

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)InGaAlAs/InGaAs/InGaAlAs/InAs/InP quantum-dot structures have been investigated for the development of infrared photodetectors capable of generating photocurrent peaks exceptionally narrow for sharp wavelength discrimination. Our specially designed structure displays a photocurrent peak at 12 mu m with a full width at half maximum, limited by inhomogeneous broadening, of only 4.5 meV. In agreement with two independent energy level calculations, we attribute this peak to photon absorption between InAs quantum dot bound states, followed by a three step carrier extraction mechanism in which the coupling to the adjacent InGaAs quantum well is a key feature. The possible role played by intraband Auger scattering, multiphoton sequential absorption and tunneling in generating the observed current peak is also addressed.481013601366WPIFWF SFB IR-ONEC NoE SANDIEConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FINEPCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ)Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES