Trapped electrons studied through stimulated neutralization luminescence

Abstract

The optically induced or ''stimulated'' neutralization luminescence (SL) following $gamma$ irradiation of rigid matrices can provide two types of information: (1) the emission spectrum characterizes the neutralization process, i.e., the neutralized cation or one of its dissociation fragments; (2) the excitation spectrum gives information on the nature and depths of the electron traps and occasionally on the trapped electrons e$sup -$/sub t/ spatial distribution. Examples of type 2 experiments performed at 77$sup 0$K on crystalline or glassy polar matrices are presented and discussed. The photodetrapping threshold values were found at 2.3 eV for ethanol glasses (lambda/ sub an/ 345 nm) and at 1.9 eV for crystalline H$sub 2$O or D$sub 2$O ices (lambda/ sub an/ 380 nm). No detrapping threshold appears in the SL spectra recorded from $gamma$-irradiated alkaline ices. (auth)