We propose a design to confine light absorption in flat and ultra-thin amorphous silicon solar cells with a one-dimensional silver grating embedded in the front window of the cell. We show numerically that multi-resonant light trapping is achieved in both TE and TM polarizations. Each resonance is analyzed in detail and modeled by Fabry-Perot resonances or guided modes via grating coupling. Thi...

We report the intrinsic and extrinsic electrical characteristics of advanced multilayer amorphous silicon (a-Si:H) thin-film transistor (TFT) with dual amorphous silicon nitride (a-SiNX:H) and a-Si:H layers. The thickness effect of the high electronic quality a-Si:H film on the transistor’s electrical property was investigated; with increasing film thickness, both field-effect mobility and subt...

The pressure-induced phase transition in amorphous silicon ~a-Si! is studied using ab initio constantpressure molecular-dynamic simulations. Crystalline silicon ~c-Si! shows a phase transformation from diamond-to-simple hexagonal at 29.5 GPa, whereas a-Si presents an irreversible sharp transition to an amorphous metallic phase at 16.25 GPa. The transition pressure of a-Si is also calculated fro...

Hydrogenated amorphous silicon betavoltaic devices are studied both by simulation and experimentally. Devices exhibiting a power density of 0.1 W/cm 2 upon Tritium exposure were fabricated. However, a significant degradation of the performance is taking place, especially during the first hours of the exposure. The degradation behavior differs from sample to sample as well as from published resu...

We present a model of size-dependent luminescence from a-Si:H and show that a blueshift of the luminescence energy and a general increase in luminescence quantum efficiency are predicted as structure size decreases. In contrast to bulk a-Si:H structures, highly confined a-Si:H exhibits visible luminescence peak energies and high radiative quantum efficiency at room temperature, which is insensi...

When prepared by conventional evaporation or sputtering, thin films of amorphous silicon contain a large concentration of defects and microvoids.3,4 These give rise to localized states in the energy gap of the material.3,4 Plasma-enhanced chemical vapor deposition (PECVD), using silicon hydrides, significantly reduces the number of defects and thereby lowers the concentration of localized state...

Thin silicon films of varying thickness were deposited on foreign substrates by electron-cyclotron resonance chemical vapor deposition from SiH4-H2 mixtures at 600 K. Optical thickness measurements, Rutherford backscattering, and transmission electron microscopy reveal that a thin amorphous interlayer of some 10 nm thickness has formed upon the substrate, before the growth of a microcrystalline...