Relaxation and recombination channels of formation of luminescent states in a neon crystal: Evidence of electron self-trapping

Abstract

The relation between the temperature and the intensity distribution in luminescence bands in VUV and VIS spectral regions of Ne crystals is investigated. The measurements are made by using cathodoluminescent spectroscopy with steady-state excitation and are supplemented by observations of luminescence decay in perfect pure crystals, in samples with defects, and in solid solutions with electronegative (oxygen) and electropositive (xenon) impurities. The contribution of the recombination channel to the formation of the spectrum of self-trapped states in solid neon is determined. It is shown that this channel plays a decisive role in the population of 3p(3p) luminescence centers and makes a relatively small contribution to the population of the lowermost 3s(3s) excitations. The recombination channel efficiency strongly depends on temperature, increasing abruptly with the temperature value. An analysis of experimental data leads to the conclusion on the possibility of electron self-trapping in Ne cryocrystals, followed by the formation of shallow self-trapped states.