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Selenium supersaturated silicon is a promising material for intermediate-band solar cells and extended infrared photodiodes. Selenium-rich Si layers were fabricated by Se ion implantation followed by pulsed laser melting using one or three pulses. The Rutherford backscattering spectrometry in random and channeling directions, the Raman spectroscopy, and photoluminescence techniques were used to study structural and optical properties of the Se-rich silicon layers. It is shown that laser irradiation leads to silicon recrystallization and significant impurity redistribution in the implanted layer. According to the Rutherford backscattering data, the substitutional fraction of Se atoms after laser treatment is 60-80%. The analysis of photoluminescence spectra revealed that pulsed laser irradiation of the implanted layer with the power density of 1.5 J/cm 2 leads to the formation of vacancy and interstitial Si clusters. After annealing at the power density higher than 1.5 J/cm 2 , the photoluminescence originating from vacancies and interstitials disappears. To explain the evolution of the Se distribution within the implanted layer after laser melting, numerical solution of the 1D diffusion equations was used.

Algorithms for the gradient method of solution of the inverse problem on determination of the nonlinear thermal-conductivity coefficients are given. Results of numerical experiments are discussed.Introduction. In [1], we consider the problem of functional identification of the nonlinear thermal-conductivity coefficient λ(T). Behind the approach proposed is the gradient method of numerical solution of inverse heat-conduction problems [2][3][4]. We note that, in the traditional approach to finding λ(T), one uses a finite-dimensional approximation of a coefficient by the system of basis functions [4], whereas in [1], we propose a method of solution of inverse heat-conduction problems without preliminary approximation of the functions sought; this method uses new representations of the operator conjugate to the internal-superposition operator, which makes it possible to obtain formulas convenient for numerical calculations of the values of the conjugate operator.In the present work, we propose algorithms of functional identification of the coefficient λ(T), describe computational experiments, and discuss calculation results.Computational Formulas. We give the formulas from [1], which are necessary for numerical realization of the algorithms of solution of inverse heat-conduction problems. The system of equations for finding λ(T) has the form