PECULIARITIES OF CARRIER RECOMBINATION IN CDXHG1-XTE IMPLANTED CONSECUTIVELY WITH AG+ (CU+) AND XE+ IONS

The influence of consecutive implantation of Ag+ (Cu+) and Xe+ ions on recombination processes in CdxHg1-xTe has been studied. It has reveal ed that after an implantation with a certain kind of ions followed by diffusion thermal annealing (DTA) at temperatures lower than 150-200 K there dominates a recombination through levels 30 +/- 5 meV below the bottom of the conduction band. After a consecutive double implantatio n of Ag+ (Cu+) and Xe+ ions followed by DTA the measured carrier minor ity lifetime tau versus temperature changes and strongly depends on th e value of x. For CdxHg1-xTe with x less than or equal to 0.25 tau(1/T ) is rather small (< 0.15 mu s) and is temperature-independent in the extrinsic region. For CdxHg1-xTe with x similar to 0.3 a recombination through two levels occurs: at temperatures 140-200 K, through a deep level E-t1 congruent to E-c - 51 meV; and at lower temperatures 100-14 0 K, through a shallower level E-t2 congruent to E-c - (16 +/- 2) meV. Thus, the peculiarities of measured minority carrier lifetime can be explained by a formation of new recombination defect complexes. (C) 19 97 Elsevier Science B.V. All rights reserved.