Abstract
Thirty-period GaAs/AlGaAs quantum-well infrared photodetector (QWIP) samples with the same device structure prepared by molecular beam epitaxy (MBE) and metal-organic chemical vapor deposition (MOCVD) are investigated in this paper. Temperature-insensitive responsivities observed for the devices are attributed to the unchanged photocurrent gain within the temperature range 10-77 K. Higher absorption for transverse electric mode infrared incident light observed for MBE-prepared QWIP is attributed to an increased interface light scattering resulted from MBE-prepared less smooth interfaces. In this case, higher normal incident absorption for the QWIP device prepared by MBE would be observed. Similar phenomenon observed for the MOCVD-prepared QWIP grown on 2° off (100) GaAs substrate is consistent with the argument. © 2008 Elsevier B.V. All rights reserved.