InTlSb for Long-Wavelength Infrared Photodetectors and Arrays

摘要

The objective of this research program is to grow InTlSb alloys for longwavelength infrared detector applications by low pressure metalorganic chemical vapor deposition (LP-MOCVD) and to investigate their physical properties. As a first step towards this goal, optimum growth conditions for high quality InSb epitaxial films on InSb, GaAs, and Si substrates have been determined. For the long wavelength applications, growth of InAsSb and InTlSb was then carried out using arsine and cyclopentadienylthallium as the source for arsenic and thallium respectively. By changing the thallium flow, thallium content was varied and the resulting absorption edge varied from 5.5 to 9.0 microns. The photoconductive detectors have been fabricated and measured using Fourier transform infrared (FTIR) spectrometer and blackbody test setup. Using the Hall data, the effective carrier lifetime and detectivity have been calculated for the InTlSb layers. These results demonstrate InTlSb as feasible material system for long wavelength infrared detection.