Introducing intermediate band(s) within the energy gap of the semiconductor could possibly increase efficiencies of solar cells. Photons with energy less than the band gap can contribute to the device output by using the intermediate band(s) as a ‘ladder’ to the conduction band. The present analysis shows the maximum efficiency an ideal solar cell containing one and two intermediate bands can a...

Recent studies have reported an interesting class of semiconductor materials that bridge the gap between semiconductors and half-metallic ferromagnets. These materials, called spin gapless semiconductors, exhibit a band gap in one of the spin channels and a zero band gap in the other and thus allow for tunable spin transport. Here, we report the first experimental verification of the spin gaple...

This paper describes synthesis of In2S3 nanoparticles by sonochemistry method and their application to enhance solar cells performance which In2S3 nanoparticles work as co-sensitizer for the first time. In2S3 is a narrow band gap semiconductor (2 eV) with conduction band higher than TiO2. Therefore it can transfer electron to the conduction band of TiO2. The effect of different parameters such ...

The band structures of fully hydrogenated Si nanosheets and nanotubes are elucidated by the use of an empirical tight-binding model. The hydrogenated Si sheet is a semiconductor with an indirect band gap of about 2.2 eV. The symmetries of the wavefunctions allow us to explain the origin of the gap. We predict that, for certain chiralities, hydrogenated Si nanotubes represent a new type of semic...

We systematically studied the physical properties of a novel superhard (t-C₃N₄) and a novel hard (m-C₃N₄) C₃N₄ allotrope. Detailed theoretical studies of the structural properties, elastic properties, density of states, and mechanical properties of these two C₃N₄ phases were carried out using first-principles calculations. The calculated elastic constants and the hardness revealed that t-C₃N₄ i...

Diamond is a promising material for the next generation of high-power and high-frequency semiconductor devices. In terms of its physical properties: high carrier saturation velocity (2.7·10 cm/s), high electron and hole mobility at low doping level, and record thermal conductivity, diamond significantly exceeds other semiconductor materials. Diamond is a wide-band gap semiconductor/insulator (b...

In this work we report the synthesis and characterization of a new nanostructured platinum/tin/telluride inorganic/surfactant composite. The material is synthesized from soluble SnTe(4)(4-) clusters and is shown to have well-defined nanometer scale periodicity along with unique optical properties. Small-angle X-ray scattering indicates that the material forms with a 2D hexagonal honeycomb struc...

Vertically aligned undoped ZnO nanotips, nanotubes and nanorods were synthesized on the top facets of Na-doped ZnO nanorods without catalytic assistance under different growth times in a chemical vapor deposition system. The growth mechanism is discussed. The Na-doped nanorods were grown on a ZnO seed layer on Si. The p-type conductivity of the Na-doped nanorods was studied by temperature-depen...

The basic requirement for a imaging low-light level system (one capable of single photon counting) is that the device has low dark current. Photocathode based devices have the advantage over solid state devices in this regard as the dark current is inherently low. A further requirement for UV detectors is the necessity to suppress the sensitivity in the red, and wide-band gap semi-conductors ll...