Luminescence of AgCl excited by u.v. laser light

The spectral distribution and decay of the blue-green luminescence of AgCl has been measured at very low temperatures, using u.v. laser excitation. A structure was observed in the emission band at 77°K. The decay consists of three processes: a) a very fast process which follows the laser pulse (10^–8 sec), b) a fast exponential process which is also observed with low intensity u.v. excitation,(10^–4–10^–5 sec) and, finally, c) a slow exponential process (seconds).     

Remarks to the origin of surface luminescence centra on AgCl in different atmospheres

Present article is devoted to the pursuit of excitation spectra and of thermal dependencies of emission spectra of photoluminescence of pure samples of AgCl during the preparation and/or annealing in argon, air, oxygen or HG1. Differences of luminescence properties of different samples are explained by the existence of different surface luminescence centres created during the preparation of samples.     

Atomic Force Microscopy Analysis of Statistical Roughness of GaAs Surfaces Originated by Thermal Oxidation

We have determined the important statistical quantities of the rough boundary between a GaAs single crystal and its oxide film formed by thermal oxidation. Thermal oxidation of the GaAs surfaces was performed at the temperature of 500°C. Using mathematical procedures developed for treating AFM data consisting of a family of the values of the heights of the irregularities of this roughness the values of the important statistical quantities of roughness were determined for 11 samples of the GaAs surfaces created by dissolution of the thermal oxide films originated during thermal oxidation of the smooth GaAs samples (the times of oxidation of these 11 samples were within interval of 20min–8 hours). From the AFM analysis of the roughness of GaAs surfaces it was found that the roughnening of these surfaces was the most pronounced for shorter oxidation times, i.e. for times smaller than about 2 hours.