Lateral conduction quantum dot infrared photodetectors using photoionization of holes in InAs quantum dots

摘要

We report on mid-infrared photoconductivity of Be-doped p-type lateral conduction quantum dot infrared photodetectors and electronic states of the valence band in InAs self-assembled quantum dots. We have observed a broad photocurrent signal in a photon energy range of 100-400 meV (lambda similar to 3-10 mu m) due to bound-to-continuum intersublevel absorption of normal incidence radiation in the valence band of InAs self-assembled quantum dots, showing a peak sensitivity around hv = 190 meV (lambda similar to 6.5 mu m). The observed responsivity was as high as 16 A W-1 at T = 10 K. Furthermore, the activation energy from ground state in the quantum dot to the valence band of GaAs was estimated to be around 100 meV.