Defects in disordered (amorphous) semiconductors are discussed, with an emphasis on hydrogenated amorphous silicon. The general differences between defect phenomena in crystalline and amorphous hosts are described, and the special importance of the electron–phonon coupling is stressed. Detailed calculations for amorphous Si are presented using accurate first principles (density-functional) tech...

Hydrogenated nanocrystalline silicon (nc-Si:H) has attracted greater attention because of its improved transport properties with respect to hydrogenated amorphous silicon (a-Si:H) [1]. In addition, its deposition conditions are compatible with amorphous silicon technology which makes it possible to use both materials in the same device. In this sense, it has been proposed as a candidate for the...

An implementation of the reverse Monte Carlo algorithm is presented for the study of amorphous tetrahedral semiconductors. By taking into account a number of constraints that describe the tetrahedral bonding geometry along with the radial distribution function, we construct a model of amorphous silicon using the reverse Monte Carlo technique. Starting from a completely random configuration, we ...

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...

The early stages of thin film growth from the rf glow discharge of silane-based gas mixtures have been systematically studied by structural characterizations of the silicon based multilayers. The x-ray diffraction, its rocking curve and x-ray interference of hydrogenated amorphous silicon(a-Si:H, 10 % 200 A thick)/stoichiometric silicon nitride (a-SigNq:H, 25 % 250 A) multiple layers have been ...

In this paper, we present a new method for direct-write laser fabrication of thin-film amorphous silicon (a-Si) on crystalline silicon substrate induced by femtosecond laser irradiation. Using megahertz frequency femtosecond laser pulses makes it possible to control laser fluence in the amorphization range of silicon under ambient condition. Finally, a thin-film of amorphous silicon is generate...

We report radial heterojunction solar cells of amorphous silicon on crystalline silicon microwires with high surface passivation. While the shortened collection path is exploited to increase the photocurrent, proper choice of the wire radius and the highly passivated surface prevent drastic decrease in the voltage due to high surface-to-volume ratio. The heterojunction is formed by depositing a...

We exploit the high χ nonlinearity present in hydrogenated amorphous silicon nanophotonic waveguides to demonstrate frequency conversion at telecommunication wavelengths using pump and signal that are both continuous-wave. We reach a frequency conversion efficiency close to -34dB having a on-chip 13mW pump power in a low-loss 1cm long silicon photonic wire. Thanks to the ultra-low pump power an...