InAs/AlxGa1-xAs quantum dot infrared photodetectors with undoped active region

We report on a study of n-type quantum dot (QD) infrared photodetectors (QD IPs) based on InAs/GaAs QDs grown via an innovative technique called punctu ated island growth. The electronic structure of the QDs inserted in QDIP de vices is comprehensively investigated with photoluminescence, and intra- an d interband photocurrent spectroscopy. The influence of AlGaAs layers inser ted in active regions on the performance of the QDIPs is examined. Bias and temperature dependence of intraband photoresponse of QDIPs with undoped ac tive region is examined. Initial results on intraband photoresponsivity and detectivity of these QDIPs at 77 K are reported. (C) 2001 Elsevier Science B.V. All rights reserved.