Alvarenga D.R.,Federal University of Minas Gerais |
Alvarenga D.R.,Disse Instituto Nacional Of Ciencia E Tecnologia Of Nanodispositivos Semicondutores |
Parra-Murillo C.A.,Federal University of Minas Gerais |
Parra-Murillo C.A.,Disse Instituto Nacional Of Ciencia E Tecnologia Of Nanodispositivos Semicondutores |
And 21 more authors.
IEEE Journal of Quantum Electronics | Year: 2012
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 μ 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. © 2012 IEEE.