Effect of neutron irradiation on the luminescence spectra of CdS single crystals

Irradiation of CdS and CdS:Cu single crystals with fast pile neutrons to high doses (F > 10(18) cm(-2)) causes an insignificant decrease in the intensity of the red (lambda similar or equal to 720 nm, T = 77 K) and infrared (lambda similar or equal to 1.03 mu m, T = 77 K) luminescence bands. The 808-nm band observed for doped samples transforms into the band at lambda similar or equal to 730 nm, and the intensity of excitonic, orange, and green emissions decreases drastically. The insignificant shift of the luminescence bands and their broadening upon neutron irradiation are attributable to electric and elastic strain fields of defect clusters, which act as effective sinks for Cu atoms in doped crystals.