ZnTe/GaSb distributed Bragg reflectors grown on GaSb for mid-wave infrared optoelectronic applications

摘要

ZnTe/GaSb distributed Bragg reflectors (DBRs) are proposed and demonstrated for mid-wave infrared (2–5 μm) optoelectronic applications. The reflectance spectra of ZnTe/GaSb DBRs are simulated using the transmission matrix method, indicating a peak reflectance higher than 99.9% for a DBR of 10 quarter-wavelength (λ/4) pairs. A series of ZnTe/GaSb DBR structures have been successfully grown on GaSb (001) substrates using molecular beam epitaxy. X-ray diffraction results reveal smooth interfaces, uniform thicknesses, and low defect density. The DBR sample of seven λ/4 pairs has a peak reflectance as high as 99.0% centered at 2.5 μm with a 480-nm wide stopband.