Minority-carrier lifetime measurements of efficient GaAlAs p-n heterojunctions

Abstract

High‐efficiency Ga_1−xAl_xAs p‐n heterojunctions have been fabricated by the temperature‐difference method (η_RT, 1–3% at 6650 A), and the deep levels which govern the efficiency and the lifetime have been studied by I‐V, C‐V, photocapacitance, impedance, and electroluminescence measurements. The lifetime obtained by the impedance measurement and the deep‐level distribution obtained by the C‐V measurement have a correlation. The lifetime for efficient diodes is as low as 1 μs at 80 K. The temperature dependence of the lifetime was also measured. Photocapacitance spectra show a threshold photon energy of 0.65 eV. Arsenic vacancies are proposed for these deep levels.