The excess carrier lifetime in vacancy‐ 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−xCdxTe wafers with x∼0.225 and Na∼1×1016/cm3, 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.