Anomalous PL brightening caused by impact formation of a (D⁺, X) complex during an impact ionization avalanche in n-GaAs

The impact formation of the (D⁺, X) bound-exciton in n-GaAs at 4.2 K during an impact ionization avalanche under an applied pulse voltage has been investigated. The bright PL-pattern observed by applying the pulse voltage characterizes well the formation of a current density filament. The observations of the bright PL-pattern give a quite new result concerning the electron-impact formation process of the excitons bound to the ionized donors (D⁺, X).