Recombination in germanium: Voltage-decay experiments on induced-junction devices and validity of the SRH model

Abstract

Measurements of open-circuit voltage decay following the application of a dark forward-current pulse have been made on induced pn-junction devices in moderately-doped germanium. Minority-carrier lifetime has been measured over a wide temperature range, as well as over a wide range of injection level. All of the results are accurately explained by the SRH model with a single acceptorlike trap level at an energy 0.128 ± 0.008 eV below the conduction band edge, i.e. above the equilibrium Fermi level in the n-type material. The dependence of the hole capture cross section on temperature is further quantitatively explained by the theory for coulombic capture of Rose, without adjustable parameters.