The controlled growth of high-quality mercury cadmium telluride

Abstract

The investigations of HgCdTe heterostructures (MCT HS) and molecular beam epitaxy (MBE) growth processes using in-situ ellipsometry were carried out. The high-quality MCT HS with low density of V-shape defects (10 2 cm −2) were grown on (103) CdTe and GaAs substrates. The MCT HS with wide band gap layers at the interface and at the surface exhibited the best electrical characteristics. The electron concentrations, mobilities and life-time of minority carriers were 2 × 10 14 − 5 × 10 15 cm −3, 50000–350000 cm 2 V −1 s −1, 10 −6 s, respectively. The hole concentrations, mobilities and life-time of minority carriers were 5 × 10 15−2 × 10 16 cm −3, above 500 cm 2 V −1 s −1, 10 −7 s, respectively. On the base of the grown MCT HS, photoconductors and photodiodes were fabricated with good photoelectrical parameters. Electron probe microanalysis studies revealed the presence of elemental tellurium inside V-shape defects. Thermodynamic calculations suggested the possibility of elemental tellurium crystallization during the MCT HS growth by MBE.