Cobalt (Co) doped Zinc Oxide (ZnO) thin films, containing different amountof Cobalt nanoparticles as the Co doping source, deposited by the sol–gel spin coatingmethod onto glass via annealing temperature at 400˚C, have been investigated by opticalcharacterization method. The effect of Co incorporation on the surface morphology wasclearly observed from scanning electron microscopy (SEM) images. ...

EMA is a method to estimate the dielectric response of a compound material [1]. We study a nanocrystalline film compound manufactured under highly nonequilibrium conditions, composed of crystalline silicon, c-Si, amorphous silicon, a-Si, and voids. The structure of crystalline silicon can be modified by introducing amorphous silicon. So, the optical properties can be changed because another pha...

A strong interaction of a semiconductor with a below-bandgap laser pulse causes a blue-shift of the bandgap transition energy, known as the optical Stark effect. The energy shift persists only during the pulse duration with an instantaneous response time. The optical Stark effect has practical relevance for applications, including quantum information processing and communication, and passively ...

Organometal halide perovskite semiconductors have emerged as promising candidates for optoelectronic applications because of the outstanding charge carrier transport properties, achieved with low-temperature synthesis. Here, we present highly sensitive sub-bandgap external quantum efficiency (EQE) measurements of Au/spiro-OMeTAD/CH3NH3Pb(I1−xBrx)3/TiO2/FTO/glass photovoltaic devices. The room-t...

It has been recently found that the initial-energy effect, which is associated with the finite initial energy of carriers entering the multiplication region of an avalanche photodiode (APD), can be tailored to reduce the excess noise well beyond the previously known limits for thin APDs. However, the control of the initial energy of injected carriers can be difficult in practice for an APD with...

Hafnium silicate films with pure HfO2 and SiO2 samples as references were fabricated by atomic layer deposition (ALD) in this work. The optical properties of the films as a function of the film composition were measured by vacuum ultraviolet (VUV) ellipsometer in the energy range of 0.6 to 8.5 eV, and they were investigated systematically based on the Gaussian dispersion model. Experimental res...

Using density functional theory and generalized gradient approximation for exchange and correlation, we present theoretical analysis of the electronic structure of recently synthesized graphyne and its boron nitride analog (labeled as BN-yne). The former is composed of hexagonal carbon rings joined by C-chains, while the latter is composed of hexagonal BN rings joined by C-chains. We have explo...

The bound electronic nonlinear refractive index, n 2 • and two-photon absorption (2PA) coefficient, 6, are measured in a variety of inorganic dielectric solids at the four harmonics of the Nd:YAG laser using Z scan. The specific materials studied are: barium fluoride (BaF2 ), calcite (CaC03), potassium bromide (KBr), lithium fluoride (LiF), magnesium fluoride (MgFz), sapphire (Ab03), a tellurit...

In order to increase the power conversion efficiency of organic solar cells, their absorption spectrum should be broadened while maintaining efficient exciton harvesting. This requires the use of multiple complementary absorbers, usually incorporated in tandem cells or in cascaded exciton-dissociating heterojunctions. Here we present a simple three-layer architecture comprising two non-fulleren...

It has been shown that the two different orientations of Stone-Wales (SW) defects, i.e. longitudinal and circumferential SW defects, on carbon nanotubes (CNTs) result in two different electronic structures. Based on density functional theory we have shown that the longitudinal SW defects do not open a bandgap near the Fermi energy, while a relatively small bandgap emerges in tubes with circumfe...