This article discusses details study on crystallization , optical properties of Li-Al-Si-La glass containing nanocrystalline LaF3.and their optical energy gaps. The Urbach energy of glass samples was evaluated. By using (2% mole) Tb the green–blue range emission occurred, while by accumulation 1% mole Gd beside Tb, the indigo emission intensity (418 to 441 nm) increased.

Review copy ± not for distribution (pss-logo will be inserted here by the publisher) pss-­‐Header will be provided by the publisher 1 Introduction The continuous random network (CRN) has become the accepted model for homogeneously disordered materials, and for good reason: such atomistic models reproduce the experimentally observed properties of the materials, including some of the finer detail...

Citation Letz, M. et al. " Temperature-dependent Urbach tail measurements of lutetium aluminum garnet single crystals. Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matte...

The evolution of the electronic absorption edge of type I, II and III kerogen is studied by diffuse reflectance UV–Visible absorption spectroscopy. The functional form of the electronic absorption edge for all kerogens measured is in excellent agreement with the ‘‘Urbach tail’’ phenomenology. The Urbach decay width extracted from the exponential fit within the visible range is strongly correlat...

Borosilicate BK7 glasses doped with different amounts of CeO2 (0.5,1,1.5%) were prepared by the convenient melting process in this work. DTA analysis proved that 0.5-1% CeO2 has a network modifier role and then up to 1.5% it shows network former role.For structural studies, FT-IR and Raman spectroscopy were carried out. Fermi energy level, direct/ indirect optical band gap and Urbach energy wer...

Nanocrystalline PbTe films are deposited on different substrates at room temperature through thermal evaporation. The films are stoichiometric single-phase polycrystalline with 200 texture. Electrical properties of the films are analyzed in the framework of a grain boundary channel conduction model. The index of refraction and extinction coefficient of PbTe films are extracted from infrared spe...

Optical spectroscopy techniques, including visible and near infrared (IR) Raman and synchrotron IR methods have been applied to study solid nitrogen at megabar pressures. We find that nitrogen becomes totally opaque above 150 GPa, accompanied by the disappearance of Raman and IR vibrational excitations, while new broad IR and Raman bands become visible. Optical absorption measurements reveal th...

The photovoltage Voc of high-performance solar cells such as GaAs and metal halide perovskites is affected by the exponential Urbach tail in absorption spectrum, with an energy parameter EU. It has been observed that increasing decreases maximum can be achieved. On basis detailed balance reciprocity emission, we present a calculation shows voltage loss due to obeys universal relation ΔVocrad = ...