Upconversion Luminescence of Er3+ Ions from Barium Titanate Xerogel Powder and Target Fabricated by Explosive Compaction Method

Journal of Applied Spectroscopy - Photo- and cathodoluminescence in the visible range from erbium-doped barium titanate xerogels obtained in the form of a powder and a target pressed from it by...     

Photoluminescence of single crystals of cadmium diarsenide

An investigation is made of the low-temperature (4.2–78 K) photoluminescence of single crystals of cadmium diarsenide grown from the gas phase and by the Bridgman method. Radiation near the fundamental absorption edge is detected, which is attributed to annihilation of free excitons with simultaneous emission of phonons (the lines 1.0029 and 0.9840 eV at 4.2 K). The optical width of the forbidden band is estimated at 4.2 K. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 1, pp. 149–152, January–February, 1998.     

Luminescence of silicon films on sapphire irradiated with high-energy particles

Using low-temperature (4.2–78 K) photoluminescence, we study the processes of defect formation in silicon films on sapphire irradiated with high-energy particles (electrons, γ-quanta of⁶⁰Co). It is established that carbon atoms, as a residual process impurity, participate in the formation of luminescence centers stable up to annealing temperatures of about 550 K. For carbon-containing centers we reveal a shift in the spectral lines relative to their position in spectra of single-crystal silicon. It is proposed that this spectral shift is associated with the presence of internal stresses of about 5·10⁸ N/m² in the silicon films. Institute of Solid-State Physics and Semiconductors, National Academy of Sciences of Belarus, 17, P. Brovka Str., Minsk, 220072, Belarus. Translated from Zhurnal Prikladnoi Spektroskefii, Vol. 66, No. 3, pp. 383–386, May–June, 1999.     

Optical and Paramagnetic Properties of Synthetic Diamond Single Crystals with a Low Content of Nitrogen

Optical and paramagnetic properties of synthetic diamond single crystals grown by the temperature gradient method in the Fe-Co-C and Fe-Co-Al-C systems using split-sphere high-pressure apparatus have been investigated. For crystals with a high (>5·10¹⁷ cm^–3) nitrogen concentration a good agreement of the concentrations of single substitution nitrogen atoms obtained from EPR, IR, and UV measurements was observed. For crystals with a low ((0.5–5.0)·10¹⁷ cm^–3) nitrogen concentration, there was no correlation between the results of substituting nitrogen concentrations obtained by the methods mentioned. It is shown that this behavior is attributable to the transition of the substituting nitrogen atoms from the paramagnetic neutral to nonparamagnetic positive charge state due to compensation by the boron impurity.     

A PL and PLE Study of High Cu Content Cu2ZnSnSe4 Films on Mo/Glass and Solar Cells

Physics of the Solid State - Cu2ZnSnSe4 (CZTSe) is amongst leading candidates for the absorber layer in sustainable solar cells. We examine CZTSe thin films with [Cu]/[Zn + Sn] of 0.99 and...     

Luminescence in the 1.54 µm region for erbium in two-dimensional and three-dimensional mesoscopic structures

We have studied the luminescence and luminescence excitation spectra of erbium in the 1.54 μm region in titanium oxide and silicon oxide xerogels, formed in the mesoscopic pores of three-dimensional synthetic opals and two-dimensional porous aluminum oxide structures. For erbium-doped titanium oxide films formed in opal, in contrast to analogous films on porous aluminum oxide, in the luminescence excitation spectra we observe an intense broad band with a maximum in the ∼360 nm region. We discuss the possible nature of this band. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 5, pp. 622–626, September–October, 2007.     

Ion-beam synthesis of InAs nanocrystals in crystalline silicon

The formation of nanodimensional InAs crystallites on Si wafers was studied by the method of high-fluence implantation of As and In ions with subsequent high-temperature treatment. It was found that the size and depth distributions of the crystallites depend on both the implantation temperature and the annealing conditions. A broad band in an energy range of 0.75–1.1 eV was recorded in the photoluminescence spectra of the samples.