Normal-incidence voltage-tunable middle- and long-wavelength infrared photoresponse in self-assembled InAs quantum dots

We report the realization of electron intraband absorption based middle~;5.6 mm! and long~;10 mm! wavelength infrared ~IR! photoresponse for normally incident radiation on InGaAs-capped GaAs~001!/InAs quantum dots ~QDs! in a n – i(QD) – n structure. The relative photoresponse in this dual-wavelength structure is tunable up to two orders of magnitude with bias. The full width at half maximum of the long-wavelength IR intraband photocurrent peak at 80 K is as narrow as 8.2 meV. © 2002 American Institute of Physics. @DOI: 10.1063/1.1467974#