We report on a temperature-dependent band gap property of epitaxial MoSe2 ultrathin films. We prepare uniform MoSe2 films epitaxially grown on graphenized SiC substrates with controlled thicknesses by molecular beam epitaxy. Spectroscopic ellipsometry measurements upon heating sample in ultra-high vacuum showed temperature-dependent optical spectra between room temperature to 850 °C. We observe...

The design of one-dimensional photonic crystals and the analysis of their optical properties have been performed using band diagram and forbidden gap map methods. It has been shown that the latter method is more useful for practical applications since i it can be applied for any number of periods and ii it is more suitable for the selection of a filling fraction in a wide range of values using ...

Organometal halide perovskites are promising materials for optoelectronic devices. Further development of these devices requires a deep understanding of their fundamental structure-property relationships. The effect of pressure on the structural evolution and band gap shifts of methylammonium lead chloride (MAPbCl3) was investigated systematically. Synchrotron X-ray diffraction and Raman experi...

It has been predicted that application of a strong electric field perpendicular to the plane of bilayer graphene can induce a significant band gap. We have measured the optical conductivity of bilayer graphene with an efficient electrolyte top gate for a photon energy range of 0.2-0.7 eV. We see the emergence of new transitions as a band gap opens. A band gap approaching 200 meV is observed whe...

The research in new organic π-conjugated molecules with specific properties has become one of the most interesting topics in fields of materials chemistry. These materials are promising for optoelectronic device technology such as solar cells. On the other hand, the use of low band gap materials is a viable method for better harvesting of the solar spectrum and increasing its efficiency. The Co...

Undoped and Tin (Sn) doped Molybdenum trioxide (α-MoO3) nanostructured thin films (which has lamellar (2D) structure) have been prepared using a simple and cost effective technique of spray pyrolysis on glass substrates at 450 ℃. Surface morphology, optical and structural properties of samples have been investigated using FESEM, UV-Vis spectroscopy and XRD analysis techniques, respectively. FES...

well-defined crystalline pbse nanocubes and nanospheres have been synthesized through a simple hydrothermal method by using pb2+- edta and pb2+- oleylamine complexes at 180°c for different reaction times. composition and morphology of the samples have been characterized by means of xrd and sem. gradual release process of pb2+ from pb2+-edta and pb2+-oleylamine complexes can adjust the growth ra...