High-performance narrow-bandwidth multicolor InAs/AlGaAs/GaAs quantum dot infrared photodetector
Journal
Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers
Journal Volume
44
Journal Issue
8
Pages
6307-6311
Date Issued
2005
Author(s)
Abstract
By introducing a 2nm Al0.3Ga0.7As cap layer on InAs/GaAs quantum dots, a high-performance narrow-bandwidth multicolor quantum dot infrared photodetector (QDIP) with peak responses at 5.4, 9.5, and 15.8 μm was fabricated successfully. The highest peak responsivities reached 0.79, 0.47, and 0.63 A/W at a bias of - 1.2V. The two shorter-wavelength responses originating from two different-sized InAs quantum dots were due to the transitions of InAs quantum dots from the ground state to the GaAs conduction band. The separation of the two peaks was amplified by the insertion of the 2 nm AlGaAs cap layer. The longer-wavelength peak at 15.8 μm was due to the transition from the ground state to the first excited state followed by the tunneling out of small quantum dots. The increase in photocarrier lifetime by the barrier is proposed to explain the very high responsivity. © 2005 The Japan Society of Applied Physics.
Subjects
InAs; Photoluminescence; Quantum dot infrared photodetector; Responsivity; Solid source MBE
Other Subjects
Aluminum compounds; Bandwidth; Gallium compounds; Ground state; Infrared detectors; Photoluminescence; Semiconductor quantum dots; InAs; Responsivity; Solid source MBE; Indium compounds
Type
journal article