Temperature dependence of the average energy per electron-hole pair in silicon and germanium

Abstract The temperature dependence of the average energy ∊ required per electron-hole pair has been measured between 10 and 190°K in silicon and germanium radiation detectors, for both γ-ray and α-particle bombardments. The counters were prepared with the most recent techniques in order to minimize charge carrier losses. For example, ultra high purity germanium and ion implanted contacts have been employed. The temperature dependence was found to be the same for α and γ radiations in germanium but not in silicon, and also to be weaker than previously reported. The variation with indirect bandgap E g was linear in all cases with a slope Δ∊/ΔE g equal to 1.95 for germanium and 1.85 and 2.50 in silicon, respectively for α-particles and γ-rays.