High temperature operated (/spl sim/250 K) photovoltaic-photoconductive (PV-PC) mixed-mode InAs/GaAs quantum dot infrared photodetector

The 10 stacked self-assembled InAs/GaAs quantum dot infrared photodetector (QDIP) operated in 2.5 to 7 /spl mu/m range by photovoltaic (PV) and photoconductive (PC) mixed-mode near room temperature (/spl sim/250 K) was demonstrated. The specific peak detectivity D* is 2.4/spl times/10/sup 8/ cm-Hz/sup 1/2//W at 250 K. The confining Al/sub x/Ga/sub 1-x/As barrier layers on both sides of stacked QD structure are the key to the high temperature operation.