The analogy between electromagnetic wave propagation in multidimensionally periodic structures and electronwave propagation in real crystals has proven to be a fruitful one. Initial efforts were motivated by the prospect of a photonic band gap, a frequency band in three-dimensional dielectric structures in which electromagnetic waves are forbidden irrespective of the propagation direction in sp...

We introduce a new transistor architecture based on inter-band tunneling mechanism as a step towards exploring steep switching transistors for energy efficient logic applications. While there have been reports on tunnel transistors in Si, Ge material system and their alloys, we focus specifically on narrow gap compound semiconductor (CS) systems to develop tunnel transistors. We address the fol...

Multiple exciton generation (MEG) is a process whereby multiple electron-hole pairs, or excitons, are produced upon absorption of a single photon in semiconductor nanocrystals (NCs) and represents a promising route to increased solar conversion efficiencies in single-junction photovoltaic cells. We report for the first time MEG yields in colloidal Si NCs using ultrafast transient absorption spe...

Mg2Si with narrow band gap has attracted increasing interest for its great potential applications. Theoretical calculations have predicted the metallization of Mg2Si under high pressure. In this work, the electrical resistance and Raman spectrum measurements of semiconducting Mg2Si were performed to investigate the metallization of Mg2Si by using diamond anvil cells and strip opposite anvils. A...

The paper presents a review about synthesis and applications of Ag2S nanostructures. As the modern photoelectric and biological materials, Ag2S nanomaterials are potentially useful for both structure and function purposes. Ag2S is a direction narrow band gap semiconductor with special properties. Ag2S nanostructures have been widely researched in chemistry and biochemistry fields because of the...

The influence of n-type doping CdO with In or Y has been investigated by high-resolution ultraviolet and x-ray photoemission spectroscopy. It is found that core levels and valence band features suffer a shift to high binding energy due to doping. However this shift is less than the change in the width of the occupied conduction band. This provides a direct measurement of band gap shrinkage as a...

The optical properties of 1-methyl-1,2,3,4,5-pentaphenylsilole thin films grown on silicon substrate were investigated using spectroscopic ellipsometry ~SE!. Accurate refractive index n and extinction coefficient k, in the wavelength range of 250 to 800 nm, were determined. Sellmeier equations, amorphous semiconductor model, and a three-oscillator classical Lorentz model were used to fit the da...

An electron-hole plasma recombination model is used to fit the room-temperature electroluminescence from metal–oxide–silicon tunneling diodes. The relatively narrow line shape in the emission spectra can be understood by the quasi-Fermi level positions of electrons and holes, which both lie in the band gap. This model also gives a narrower band gap than that of bulk silicon. The surface band be...

The extract of Jambol o (java plum), Eugenia jambolana Lam, was used as a natural sensitizer of a wide band-gap semiconductor (TiO2) in photoelectrochemical solar cells. The natural dye, adsorbed onto the semiconductor surface, absorbs visible light and promotes electron transfer across the dye/semiconductor interface. Photogenerated current and voltage as high as 2.3 mA and 711 mV, respectivel...