Single and double photoinjections prove to be a useful tool for investigations of recombination mechanisms. The photodischarge of selenium electrophotographic layers due to double and single photo-injections has been investigated. Experimental results show that every photoproduced pair of free carriers either recombines independently of the other free carriers or takes part in the photodischarge without subsequent recombination. This recombination explains energy-dependent quantum efficiency in the 2.5-eV (and greater) spectral region.
Supplement on Electrophotography
J. Viscakas, V. Gaidelis, A. Matulionis, E. Montrimas, and A. Šatas, "Recombination in Selenium Electrophotographic Layers," Appl. Opt. 8, 27-29 (1969)