Majority Carrier Lifetime in Copper Doped Germanium at 20°K†

Abstract

The time constant for recombination of a hole with a negatively charged copper impurity centre in germanium at 20°k has been derived from experimental data from two independent methods based on measurement of (a) the photoconductive sensitivity and (b) the semiconductor shot noise. Both methods give good agreement in order of magnitude, but the theoretical values are several orders of magnitude greater. In the range of copper concentration used (2 = l0¹⁴ to 5 = 10¹⁵ cm⁻³) the recombination time constants should decrease as the impurity concentration rises ; this is not observed.