A detailed study of the performance of compressively strained p-type III-V quantum well infrared photodetectors (p-QWIPs) is presented in this work. Three device structures composed of InGaAs/GaAs, InGaAs/AlGaAs, and InGaAs/AlGaAs/GaAs for normal incidence absorption have been fabricated and analyzed, with the results being compared with similar reported unstrained p-QWIPs. In all three QWIP structures, the quantum well layers are under biaxial compressive strain ranging from -0.8 to 2.8 percent, while the barrier layers are lattice matched to the substrate. The detection peaks of the quantum well infrared photodetectors ranged from 7.4 micrometers to 10.4 micrometers . The detectors utilized the bound-to-continuum, bound-to-quasi- bound, and step bound-to-miniband intersubband transitions for infrared detection. The results showed that responsivities of up to 90 mA/W and detectivities from 10⁹ to over 10¹⁰ cm (root) Hz/W are achieved under moderate applied bias and at reasonable operating temperatures, demonstrating the viability of the strained layer p-doped quantum well infrared photodetectors for staring focal plane array applications.

Date Published: 15 April 1997
PDF: 12 pages
Proc. SPIE 2999, Photodetectors: Materials and Devices II, (15 April 1997); doi: 10.1117/12.271183

Published in SPIE Proceedings Vol. 2999:
Photodetectors: Materials and Devices II
Gail J. Brown; Manijeh Razeghi, Editor(s)