Recombination analysis in 10 μm Pb1−xSnxTe

Stationary photoeffects are measured in annealed Pb1−xSnxTe single crystals by means of a helium-neon laser (λ = 1.15 μm). From photoconductivity and PEM effects, majority carrier and minority carrier lifetimes are evaluated, respectively. At T = 77 K lifetimes 10−12 s<τPEM<10−8s are found. Absolute values as well as temperature dependence of lifetimes are explained in term of Shockley-Read centres with activation energies from 30 to 50 meV. In TSM-grown p-type samples, minority carrier trapping is observed.