Growth of long wavelength infrared MCT emitters on conductive substrates

Uncooled operation of Auger suppressed fully doped mercury cadmium telluride (MCT) devices designed by Ashley and Elliott1 and grown by metalorganic vapor phase epitaxy (MOVPE) by Maxey et al.2 has been demonstrated. These devices also demonstrate efficient negative luminescent emission in the long wavelength infrared (LWIR) spectra.3 However, to operate a large area device (>1 cm2) requires a large current (∼10 A), and consequently, it is critical that the series resistance is minimized. To increase optical efficiency, deep optical concentrators are needed. Similar InSb molecular beam epitaxy (MBE) devices utilize a highly doped InSb substrate which allows a conduction path into the substrate with reduced series resistance and acts as an optical window (due to Moss-Burstein shift) allowing transmission of the 6 m IR emission. A suitable high conductivity substrate for MCT emitter devices is required to have a sheet resistivity of