Electronic processes in semiconductor materials studied by nanosecond time-resolved microwave conductivity. 1. Cadmium sulfide macroscopic crystal

摘要: The transient conductivity resulting from pulsed irradiation (with 3-MeV electrons) of a single, high-resistivity (4 {times} 10{sup 7} {Omega} m) crystal CdS has been studied by nanosecond time-resolved microwave conductivity. ratio the electron-hole pair mobility to formation energy is determined be 42 {plus minus} 6 {minus}4} m{sup 2} V{sup {minus}1} s{sup {minus}1}/eV. For end-of-pulse concentrations less than ca. 19} {minus}3}, half-life electrons toward localization was 25 ns. With increasing concentration above this value, lifetime found become longer. This effect attributed trap saturation with estimated 3 {minus}3} (5 {minus}8} M) rate constant trapping 1.1 {minus}12} 3} (6.6 14} M{sup {minus}1}). main site thought singly ionized sulfur vacancy. No evidence for occurrence direct recombination, and an upper limit {minus}14} (ca. 2 13} {minus}1}) could placed on second-order process.