Optically-stimulated desorption of 'hot' excimers from pre-irradiated Ar solids

TL;DR

This study demonstrates that optical stimulation can induce desorption of vibrationally excited argon molecules from pre-irradiated solid argon, revealing a new mechanism involving recombination of self-trapped holes and electrons released by visible photons.

Contribution

It introduces the first observation of optically-stimulated desorption of 'hot' argon excimers from pre-irradiated solid argon, highlighting a novel recombination process triggered by visible light.

Findings

First observation of desorption of vibrationally excited Ar2^*(v) molecules.

Desorption caused by recombination of self-trapped holes with electrons.

Optical stimulation effectively triggers the desorption process.

Abstract

Electronically-induced desorption from solid Ar pre-irradiated by a low-energy electron beam was investigated by activation spectroscopy methods - photon-stimulated exoelectron emission and photon-stimulated luminescence in combination with spectrally-resolved measurements in the VUV range of the spectrum. Desorption of vibrationally excited argon molecules Ar2^*(v) from the surface of pre-irradiated solid Ar was observed for the first time. It was shown that desorption of 'hot' Ar2^*(v) molecules is caused by recombination of self-trapped holes with electrons released from traps by visible range photons. The possibility of optical stimulation of the phenomenon is evidenced.