Quantum-dot infrared photodetector with lateral carrier transport

In this letter, we present a normal-incident quantum-dot infrared photodete ctor. The detection principle is based on intersubband transition between t he p states and the wetting-layer subband in the conduction band of self-as sembled In(Ga)As/GaAs quantum dots. Carrier transport takes place in a chan nel next to the quantum-dot layers. The photoresponse is peaked at lambda = 6.65 mum (186 meV) and reaches a maximum value of over 11 A/W at T=30 K wit h a wavelength resolution of 12%. Detector response time tau is determined to be about 0.8 ms. Temperature and frequency dependence of the detector st ructure are discussed. (C) 2001 American Institute of Physics.