RECENT RESULTS ON METALORGANIC VAPOR-PHASE EPITAXIALLY GROWN HGCDTE HETEROSTRUCTURE DEVICES

The ability to grow complex multilayer structures in Hg1-xCdxTe by epi taxial techniques has made it possible to produce a range of new devic es such as infrared LEDs, lasers, and two-color infrared detector arra ys. The devices described here, however, are designed to operate at te mperatures above 145K and include both infrared sources and detectors. Three layer ppn structures, where the underlined symbols mean wider g ap, have close to Auger limited R(0)As at temperatures above 145K. Und er reverse bias, the devices exhibit Auger suppression leading to usef ul detectivities at room temperature. The diodes exhibit forward biase d electroluminescence at room temperature although the efficiency of t his emission is found to fall rapidly as the peak wavelength is increa sed toward 9 mu m due to increased Auger recombination rates. By rever se biasing them, however, the devices show negative luminescence as a result of reducing the electron and hole densities below their thermal equilibrium value. The diode emitters have a higher quantum efficienc y when used in this mode due to Auger suppression of the dark current.