We present a novel model to describe conduction band of GaNxAs1−x (GaNAs). As well known, GaNAs shows exotic behavior such as large band gap bowing. Although there are various models to describe the conduction band of GaNAs, origin of the band gap bowing is still under debate. On the basis of perturbation theory, we show that the behavior of conduction band is mainly arising from intervalley mi...

An active, photonic band gap-based microcavity emitter in the near infrared is demonstrated. We present direct measurement of the spontaneous emission power and spectrum from a microcavity formed using a two-dimensional photonic band gap structure in a half wavelength thick slab waveguide. The appearance of cavity resonance peaks in the spectrum correspond to the photonic band gap energy. For d...

During recent years, we have observed a rapidly growing interest in the design and fabrication of novel types of photonic-crystal structures possessing large absolute band gaps. The study of various geometries of three-dimensional photonic crystals and different ways to enlarge their absolute band gaps is a key issue in the physics of periodic dielectric structures, where different polarization...

The study reports on the effects of different concentration of palladium impurities on the compositional and optical properties of Palladium Doped Antimony Sulphide (Pd-xSb2S3) thin films grown by the chemical bath deposition method. The films were grown at room temperature and other deposition conditions such as the bath temperature, pH, complexing agents were kept constant. The concentration ...

Study of the band–gap shift in CdS films: Influence of thermal annealing in different atmospheres. Abstract We study by photoacoustic spectroscopy the band–gap shift effect of CdS films. The CdS films were grown by chemical bath deposi-tion and exposed to different annealing atmospheres over a range of temperature in which the sample structure is observed to change. We show the band–gap evoluti...

The band gap dependencies of the threshold current and its radiative component are measured using high pressure techniques. Detailed theoretical calculations show that the band gap dependence of the internal losses plays a significant role in the band gap dependence of the radiative current. Temperature dependence measurements show that the radiative current accounts for 20% of the total thresh...

Using an external electric field, one can modulate the band gap of Bernal stacked bilayer graphene by breaking the A-[Formula: see text] symmetry. We analyze strain effects on the bilayer graphene using the extended Hückel theory and find that reduced interlayer distance results in higher band gap modulation, as expected. Furthermore, above about 2.5 Å interlayer distance, the band gap is direc...

Opening up a band gap in graphene holds a crucial significance in the realization of graphene-based electronics. Doping with organic molecules to alter the electronic properties of graphene is perceived as an effective band gap engineering approach. Using the tight binding model, we examined the band gap opening of monolayer graphene due to the adsorption of pyrene molecules on both of its side...

Tuning the photonic band gap (PBG) to the electronic band gap (EBG) of Au/TiO2 catalysts resulted in considerable enhancement of the photocatalytic water splitting to hydrogen under direct sunlight. Au/TiO2 (PBG-357 nm) photocatalyst exhibited superior photocatalytic performance under both UV and sunlight compared to the Au/TiO2 (PBG-585 nm) photocatalyst and both are higher than Au/TiO2 withou...

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...