Quantum efficiency and radiative lifetime in degenerate n-type GaAs

• Published in: The Journal of physics and chemistry of solids 1981, Vol.42 (2), p.95-99
• Main Author: Van Cong, H.
• Format: Article
• Language: English
• ISSN: 0022-3697; 1879-2553
• DOI: 10.1016/0022-3697(81)90094-9

The hole lifetime, the radiative lifetime, the non-radiative lifetime, and the internal quantum efficiency in degenerate n-type GaAs crystals have been investigated with a simplified model of degenerate semiconductors, in which the recombination constant B is approximately proportional to the −13 8 power of the electron density. In n-type GaAs at 77 K, the radiative lifetime reaches a minimum equal to 4 × 10 −9 sec. at 6 × 10 17 cm −3, and the internal quantum efficiency exhibits a maximum equal to 50% at 8 × 10 17cm −3, in good agreement with the theoretical prediction of Dumke and the experiments of Cusano. At high impurity concentrations, the polytropy effect is taken into account in the case of GaAs crystals doped with tellurium and selenium. Finally, it is suggested that, for a given high concentration, the internal quantum efficiency increases with increasing temperature, in accordance with the observed results.