Study of valence-band intersublevel transitions in InAs/GaAs quantum dots-in-well infrared photodetectors

Abstract

The n-type quantum dot (QD) and dots-in-well (DWELL) infrared photodetectors, in general, display bias-dependent multiple-band response as a result of optical transitions between different quantum levels. Here, we present a unique characteristic of the p-type hole response, a wellpreserved spectral profile, due to the much reduced tunneling probability of holes compared to electrons. This feature remains in a DWELL detector, with the dominant transition contributing to the response occurring between the QD ground state and the quantum-well states. The biasindependent response will benefit applications where single-color detection is desired and also allows achieving optimum performance by optimizing the bias. V C 2014 AIP Publishing LLC.

InAs/GaAs quantum dot and dots-in-well infrared photodetectors based on p -type valence-band intersublevel transitions

“…The dashed lines are the calculated using an effective-mass method. The labeled HH1-HH3 are the levels of the In 0.15 Ga 0.85 As/GaAs QW[13]. Indicated transitions agree with the experimental response.…”

“…1(a) and (b), respectively [12,13]. The absorbing region consists of 10 periods of InAs QDs, between which is an 80-nm thick undoped GaAs layer.…”

“…In this article, we discuss p-type InAs/GaAs QDIP [12] and DWELL [13] detectors, operating based on the valence-band intersublevel hole transitions. The use of p-type hole response shows promising characteristics; for example, a quantum efficiency of [15][16][17][18][19] Contents lists available at ScienceDirect Infrared Physics & Technology j o u r n a l h o m e p a g e : w w w .…”

Influence of delta-doping on the hole capture probability in Ge/Si quantum dot mid-infrared photodetectors

“…Most of the demonstrations of QDIPs were achieved with n -type III to V self-assembled nanoheterostuctures. Only limited studies of p -type QDIPs have been reported [ 3 , 4 ]. The attractive features of p -QDIPs include a well-preserved spectral profile [ 3 ], as an opposite to a conventional n -type response strongly dependent on applied bias, increased density of states, and lower dark current due to the higher hole effective mass [ 4 ].…”