cumn2o4 nanoparticles, a semiconducting materials with tunable functionalities in solid oxide fuel cell, was successfully synthesized via a sol-gel method using its respective metal cations sources i.e. cu2+ and mn2+ in an appropriate complexing agent.the vibrational frequencies below 1000 cm-1 of the obtained materials confirmed the formation of metal-oxygen (m-o:cu-o, mn-o) bond in the sample...

Further improvement of the power conversion efficiencies of conventional perovskite ferroelectric oxides has been strongly impeded by their wide band gaps. Here, we use several band gap engineering strategies to design low band gap ferroelectric materials from first principles. We show that polarization rotation is useful for reducing the band gaps of strongly distorted perovskites. A variety o...

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...

g-C3N4 is a promising material for hydrogen production from water via photo-catalysis, if we can tune its band gap to desirable levels. Using a combined experimental and ab initio approach, we uncover an almost perfectly linear relationship between the band gap and structural aspects of g-C3N4, which we show to originate in a changing overlap of wave functions associated with the lattice consta...

We study the local states within the polariton band gap that arise due to deep defect centers with strong electron-phonon coupling. Electron transitions involving deep levels may result in alteration of local elastic constants. In this case, substantial reversible transformations of the impurity polariton density of states occur, which include the appearance/disappearance of the polariton impur...

InN films with free electron concentrations ranging from mid-10 to mid-10 cm have been studied using optical absorption, Hall effect, and secondary ion mass spectrometry. The optical absorption edge covers a wide energy range from the intrinsic band gap of InN of about 0.7 to about 1.7 eV which is close to the previously accepted band gap of InN. The electron concentration dependence of the opt...

Infrared absorption measurements of amorphous and crystalline nanoparticles of GeTe reveal a localized surface plasmon resonance (LSPR) mode in the crystalline phase that is absent in the amorphous phase. The LSPR mode emerges upon crystallization of amorphous nanoparticles. The contrasting plasmonic properties are elucidated with scanning tunneling spectroscopy measurements indicating a Burste...

zno nanorod was prepared by microwave assisted method. the crystal structure of the nano powders were confirmed by x-ray diffraction analysis and the mean particle size was estimated by the scherrer,s formula .the surface morphology of the nano particles were analyzed by   using sem . the absorption spectrum of the material in the uv-vis range was recorded .the energy band gap of the material w...

CF4 plasma-passivation enhanced size dependence of the blueshift in photoemission and photoabsorption, E2p-level shift, and band-gap expansion of porous silicon has been measured and analyzed numerically based on the recent “bond order-length-strength” correlation [C. Q. Sun, Phys. Rev. B 69, 045105 (2004)]. Matching predictions to the measurements conducted before and after fluorination reveal...

Compared to the long history of plasmonic gratings, there are only a few studies regarding the bandgap in the propagation of plasmonic surface waves. Considering the previous studies on interpretation of plasmonic bandgap formation, we discuss this phenomenon using the effect of both surface plasmon polariton (SPP) and localized surface plasmon (LSP) for our fabricated one-dimensional metallic-...