MINORITY-CARRIER LIFETIME IN INDIUM-DOPED N-TYPE HG0.78CD0.22TE LIQUID-PHASE-EPITAXIAL FILMS

The recombination mechanisms of the minority-carrier lifetime in n-type indium-doped Hg0.78Cd0.22Te liquid-phase-epitaxial films have been studied. Its temperature dependence was measured from 78 to 200 K using standard photoconductivity decay method. The dependence on doping concentration from 1 X 10(14) to 2 X 10(15) cm-3 was measured using a contactless microwave reflection method at 77 K. From best fits to the experimental temperature dependence data, it was found that lifetimes at temperatures higher than 130 K were dominated by Auger recombination with a value of 0.15 for the overlap integral of Bloch functions. For most films with a doping concentration below 1 X 10(15) cm-3, Shockley-Read-Hall recombination via an acceptor-like deep level at about 40 meV below the conduction band affected lifetimes below 120 K. It was also found that the recombination parameters determined from fitting the lifetime versus temperature curves were adequate to analyze and understand the lifetime versus doping concentration curve, which comprised data from over 100 films.