LaTiO2N nanopowders (NPs) with low surface defect density via nitridation of flame made NPs retaining simple perovskite structure

LaTiO2N NP synthesized from flame made LaTiO3 NP exhibits less absorption background above the optical absorption edge than that synthesized from flame made La2Ti2O7 NP, suggesting a low surface defect density.

Temperature dependence of the optical absorption edge of doped gallium arsenide

The temperature dependences of the optical absorption edges of Zn doped GaAs semiconductor crystals have been measured from 300 to 560 K. The temperature dependence of the optical absorption in the Urbach edges is adequately reproduced by a Bose-Einstein model. Analysis of experimental results gave us the opportunity to offer an explicit function of two arguments (photon energy and temperature) for the absorption coefficient of doped crystals in the Urbach edge region.

EFFECT OF THE CAPPING AGENT ON THE OPTICAL ABSORPTION EDGE OF COPPER OXIDE NANOPARTICLES FILM

In this work, the capped and uncapped copper oxide (CuO) nanoparticles film with an average size ranging from 8.7- 6.2 nm have been prepared by a chemical wet procedure using copper (II) sulfate with sodium hydroxide at 50 °C. The EDTA was used as a capping agent and the obtained samples were investigated by UV visible spectrum. The uncapped and EDTA capped CuO nanoparticles reveals two bands observed at 310 nm and 232 nm for uncapped and EDTA capped CuO nanoparticles respectively. The optical absorption spectra exhibits the energy band gap for uncapped and EDTA capped (CuO) in the range of (3.8 - 4.5) eV respectively.