Two-stack indirect-barrier/triple-coupled quantum well infrared photodetector for mid-wavelength and long-wavelength infrared detection

摘要

Abstract: We report a two-stack indirect-barrier (IB-) GaAs/Al$- 0.55$/Ga$-0.45$/As quantum well infrared photodetector (QWIP) for mid-wavelength infrared (MWIR) and a voltage-tunable In$- 0.05$/Ga$-0.95$/As/GaAs/Al$-0.19$/Ga$-0.81$/As triple-coupled (TC-) QWIP for long-wavelength infrared (LWIR) detection. We also investigate the performance dependence of this stacked QWIP with different quantum well periods (20-period and 40- period). The peak responsivity of the 20-period stacked-QWIP at zero bias (PV mode) was found to be 30 mA/W at $lambda$-p$/ equals 4.3 micrometer and T equals 40 K. The maximum peak responsivity (PC mode) was found to be 0.25 A/W at $lambda$- p$/ equals 4.3 micrometer, V$-b$/ equals $MIN@4 V, and T equals 40 K for the 20-period MWIR IB-QWIP. For the LWIR TC- QWIP, the peak wavelength due to (E$-1$/ $YLD E$-3$/) transition shifts from 10 micrometer to 9.4 micrometer as bias voltage changes from 5 to 7 V and from 9 to 14 V for 20-period and 40 period devices, respectively. A peak responsivity of 0.16 A/W was obtained at $lambda$-p$/ equals 9.4 micrometer, V$-b$/ equals 7 V, and T equals 40 K for the 20-period TC- QWIP. The results show that simultaneous detection of IR radiation at both the MWIR and LWIR bands can be achieved at V$-b$/ greater than or equal to 7 V or V$-b$/ less than or equal to $MIN@5 V for the 20-period stacked QWIP. It is shown that this two-stack QQWIP can be used as a wavelength-tunable IR detector for the MWIR and LWIR bands. !15