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.

No abstract

The Si layers doped with Te up to the concentrations of (3–5)1020 cm–3 have been formed via ion implantation and pulsed laser melting. It is found, 70–90 % of the embedded impurity atoms are in substitution states in the silicon lattice. These layers have revealed significant absorption (35–66 %) in the wavelength λ range of 1100–2500 nm. In this case, the absorption coefficient increases with the λ growth. The absorption spectra of the implanted layers after pulsed laser melting, equilibrium furnace annealing, and rapid thermal annealing have been compared. It is shown that equilibrium furnace annealing increases the photon absorption by 4 % in the wavelength range of 1100–2500 nm in comparison with virgin Si. After rapid thermal annealing, the photon absorption in the IR-range increases only by 2 %.

No abstract

The article describes the requirements for air ion generators used in air ion concentration working standards and gives the results of the tests of air ion generators designed in accordance with these requirements.