A technique for controlling the course of surface processes involving adsorbed metal clusters in luminescent condensed media

Abstract

Despite the huge amount of work devoted to the study of photostimulated processes (PSP) in crystals with a mixed type of communication, the problem of the development and improvement of information and measurement methods for monitoring the physical parameters of objects of several nanometers and the development of evaluation criteria for the use of such methods today remains relevant. From a practical point of view, relevant is the problem of developing information-measuring methods on the basis of kinetic models of the processes that allows us to offer algorithms for the application of new methods to control the processes of nucleation and modification of centers involving ions or metal atoms in crystals with a mixed type of communication, how it relates to a broad class of semiconductors. The problem of control of parameters of technological processes at early stages of new phase origin on the surface of condensed media is described. The possibility of applying the photostimulated luminescence flash (PSLF) method for luminescent crystals with ion-covalent bond is analyzed. The basic formulas allowing to estimate change of concentration of the metal particles adsorbed on a surface are resulted. The dependences of the photostimulated luminescence flash parameters on the concentration of processing solutions, which leads to the formation of clusters of varying degrees of dispersion, are considered. The model of description of process of formation of clusters from adsorbed atoms of metal is resulted. The estimation of the parameters of the centers of localization of non equilibrium charge carriers showed that within the framework of the proposed model it becomes possible to estimate the size of unstable adsorbed metal clusters. For the sample CDs: Ag, the size of such clusters was 5-7 atoms. It is proposed to use the correlation and regression model to describe the parameters of FSVL as a tool for assessing the applicability of the photostimulated luminescence flash method for monitoring surface processes on ion-covalent crystals of AgCl, ZnS, CDs. The best value of the criterion of applicability of the model FSWL was obtained for the crystal of AgCl (R2?1). For the crystals CDs the proposed method of control of technological processes must be developed according to the measurement parameters FSVL.