Monte Carlo Method is used to simulate a double layer gadolinium-amorphous silicon thermal neutron detector. The detector fabricated in pixel array configuration has various applications including neutron imaging. According to the simulation results, a detector consisting of a gadolinium (Gd) film with thickness of 2-4 ~m, sandwiched properly with two layers of sufficiently thick (-30 ?µm) hydr...

TiO2 films were grown on silicon substrates by atomic layer deposition (ALD) using tetrakis-dimethylamino titanium and ozone. Amorphous TiO2 film was deposited at a low substrate temperature of 165°C, and anatase TiO2 film was grown at 250°C. The amorphous TiO2 film crystallizes to anatase TiO2 phase with annealing temperature ranged from 300°C to 1,100°C in N2 atmosphere, while the anatase TiO...

The evolution of microstructure during Au-mediated solid phase epitaxial growth of a SixGe12x alloy film on Si~001! was investigated by in situ sheet resistance measurements, x-ray diffraction, conventional and high-resolution transmission electron microscopy, energy dispersive x-ray spectroscopy, and Rutherford backscattering spectrometry. Annealing amorphous-Ge/Au bilayers on Si~001! to tempe...

BACKGROUND The purpose of the study was to verify different values of quality parameters of portal images in radiotherapy. MATERIALS AND METHODS We investigated image qualities of different field verification systems. Four EPIDs (Siemens OptiVue500aSi(®), Siemens BeamView Plus(®), Elekta iView(®) and Varian PortalVision™) were investigated with the PTW EPID QC PHANTOM(®) and compared with two...

Intrinsic hydrogenated amorphous silicon (a-Si:H) films can yield in outstanding electronic surface passivation of crystalline silicon (c-Si) wafers as utilized in the HIT (heterojunction with intrinsic thin layer) solar cells. We have studied the correlation between the passivation quality and the interface nature between thin amorphous layers and an underlying c-Si substrate for understanding...

SiC powder preparation using Sol-Gel method. The size of nano-particles grows as the temperature exceeds 900° C. Size of probable agglomerations produced, is approximately less than 50nm. The surface is suitable to be used for dye solar cells. SiC emission occurs at wavelength area of 11.3μm or wave number area of 884.95 cm-1. In this paper probing the nature of annealed SiC samples in mixture,...

Accurate optical methods are required to determine the energy bandgap of amorphous semiconductors and elucidate the role of quantum confinement in nanometer-scale, ultra-thin absorbing layers. Here, we provide a critical comparison between well-established methods that are generally employed to determine the optical bandgap of thin-film amorphous semiconductors, starting from normal-incidence r...

Low hole mobility currently limits the efficiency of amorphous silicon photovoltaic devices. We explore three possible phenomena contributing to this low mobility: coordination defects, self-trapping ionization displacement defects, and lattice expansion allowing for hole wave-function delocalization. Through a confluence of experimental and first-principles investigations, we demonstrate the f...