An intermediate-band-assisted avalanche multiplication in InAs/InGaAs quantum dots-in-well infrared photodetector

Abstract

The avalanche multiplication of photocurrent in InAs/InGaAs quantum dot infrared photodetectors (QDIPs) has been observed in the temperature range from 20 to 80 K. The avalanche onset voltage Vth, being larger than 1.2 V at T<55 K, is reduced to less than 0.8 V at T>60 K. This singularity of Vth indicates that intermediate-band-assisted avalanche multiplication is achieved in our dots-in-well structure, which benefits from the abrupt change of the electron occupation of the intermediate band at a temperature of approximately 55 K. The remarkable reduction of Vth for QDIP is a useful enhancement in the infrared detector’s performance.

Energy band modulation of GaAs/Al0.26Ga0.74As quantum well in 3D self-assembled nanomembranes

“…The low-dimensional properties, such as quantum size effect, quantum tunneling, Coulomb blocking, and nonlinear optical effect, are the basis of new generation of solid-state quantum devices, like QW infrared photo-detectors (QWIPs), lasers based on QW materials, etc. [1][2][3][4][5][6][7][8][9][10]. However, in conventional QW devices, only the incident light whose electric vector is parallel to the growth direction of the QW contributes to the photo-current, and so the quantum efficiency of the opto-electric device is low.…”