Conversion ratio to F-H center pairs from self-trapped excitons in alkali chloride crystals

Abstract The time delayed double excitation spectroscopy has been utilized to determine the conversion ratio to F-H center pairs from self-trapped excitons(STEL) at the lowest state (1s[sgrave]g;a1g). The final conversion ratios, ηF/(ηF+ηX), were 0.86, 0.49 and 0.20 for NaCl, KCl and RbCl at 14K, respectively. The conversion efficiency (η =ηF+ηX) from STEL to F-H center pairs(ηF) and to unknown states(ηX) were 0.25, 0.90 and 0.76 for the hole excitation to πg, while 0.03, 0.01 and 0.01 for the electron excitation to b1u, b2u or b3u, in NaCl, KCl and RbCl, respectively.