Photo-induced modifications of the substrate-adsorbate interaction in K-loaded porous glass

Abstract

The effects of visible and infrared light on potassium atoms embedded in a nanoporous glass matrix are investigated. Photodesorption by visible light enhances the atomic mobility and causes the formation of metallic nanoparticles. Two different populations of metastable clusters with absorption bands in the near-infrared and infrared are grown as a consequence of illumination. Atoms can move between the two groups through sequences of adsorption/desorption events at the pore surface. Irradiation with infrared light, instead, does not significantly enhance the atomic diffusion inside the pores. However, it induces relevant modifications of the substrate, thus changing its interaction with the assembled clusters. Consequently, infrared light alters the dynamics of the system, affecting also the evolution of non-resonant nanoparticles populations, even after the illumination sequence. These results provide new insights on the photo-induced modifications of the substrate-adsorbate interaction in nano-sized confined systems.

Low Energy Atomic Photodesorption from Organic Coatings

“…LIAD effect from bare quartz [38] and from porous alumina with Rb atoms [26] was also demonstrated. In this context, as a consequence of the tight confinement of the desorbed atoms, light-assisted formation of metallic nanoparticles was observed in Rb, Cs and K from porous glass [22][23][24][25]28,29] and also from Vycor glass [27].…”

“…Several works have been produced on the photodesorption of different atoms from organic compounds named above or porous materials [22][23][24][25][26][27][28][29] in sealed glass cells, high-vacuum chambers or photonic bandgap fibers.…”