THE EXCESS CARRIER LIFETIME IN VACANCY-DOPED AND IMPURITY-DOPED HGCDTE

The excess carrier lifetimes of numerous vacancy-and impurity-doped bulk p-type HgCdTe crystals are measured using the techniques of steady-state photoconductivity and photoconductive decay. It is shown that the steady-state minority carrier lifetimes of impurity-doped crystals can be significantly larger than those of vacancy-doped crystals. However, the transient and steady state lifetimes differ by as much as an order of magnitude at 77 K due to minority carrier trapping, and appear to be uncorrelated. For Hg1- xCdxTewafers with x ~ 0.225 and Na~ 1X 10/cm, the steady-state minority carrier lifetimes of impurity-doped crystals ranged from 1.6 to 62 ns, while those of vacancy-doped crystals ranged from 1.4 to 28 ns. © 1990, American Vacuum Society. All rights reserved.