Université de Neuchâtel

Correlation between transport properties of a-Si:H layers and cell performances incorporating these layers

Wyrsch, Nicolas ; Beck, N. ; Hof, Ch. ; Goerlitzer, M. ; Shah, Arvind

In: Journal of Non-Crystalline Solids, 1996, vol. 198-200, p. 238-241

Using the new ‘quality parameter’, μ0τ0, the authors were able to show, for the first time, a clear correlation between transport properties of a series of a-Si:H films (grown at various deposition temperatures) and the efficiency of p-i-n cells incorporating the same material as i-layer. In this paper, additional experimental data are presented sustaining, on one...

Université de Neuchâtel

The quasineutrality condition in amorphous semiconductors: Reformulation of the ‘lifetime/relaxation’ criterion

Shah, Arvind ; Hubin, J. ; Platz, R. ; Goerlitzer, M. ; Wyrsch, Nicolas

In: Journal of Non-Crystalline Solids, 1996, vol. 198-200, p. 548-551

The concepts of lifetime and relaxation semiconductors introduced by van Roosbroeck and Casey are reconsidered for amorphous semiconductors and the effect of localized states on the lifetime/relaxation criterion specified: The quantity to be considered is τρ/Td, where Td is (as before) the dielectric relaxation time, but τρ is...

Université de Neuchâtel

Structural properties and electronic transport in intrinsic microcrystalline silicon deposited by the VHF-GD technique

Goerlitzer, M. ; Torres, Pedro ; Beck, N. ; Wyrsch, Nicolas ; Keppner, Herbert ; Pohl, J. ; Shah, Arvind

In: Journal of Non-Crystalline Solids, 1998, vol. 227-230, p. 996-1000

A series of microcrystalline samples was deposited by the very high frequency glow discharge (VHF-GD) technique, with various input powers while keeping all the other parameters of deposition constant. The goal was to correlate transport and structural properties and avoid as much as possible the problem of a variation of the Fermi level between the samples. The observed decrease of the...

Université de Neuchâtel

Electronic transport in hydrogenated microcrystalline silicon: similarities with amorphous silicon

Droz, Corinne ; Goerlitzer, M. ; Wyrsch, Nicolas ; Shah, Arvind

In: Journal of Non-Crystalline Solids, 2000, vol. 266-269, p. 319-324

Undoped hydrogenated microcrystalline silicon (μc-Si:H) layers were grown by the very high frequency glow discharge (VHF-GD) technique under various deposition conditions. The electronic transport properties under illumination were investigated by means of steady-state photoconductivity and steady-state photocarrier grating methods. Similarly to hydrogenated amorphous silicon (a-Si:H), power law...

Université de Neuchâtel

Extension of the a-Si:H electronic transport model to μc-Si:H: use of the μ0τ0 product to correlate electronic transport properties and solar cell performances

Goerlitzer, M. ; Torres, Pedro ; Droz, C. ; Shah, Arvind

In: Solar Energy Materials and Solar Cells, 2000, vol. 60, no. 2, p. 195-200

The aim of this communication is to show that it is possible to extend the model of the electronic transport developed for amorphous silicon (a-Si:H) to microcrystalline silicon (μc-Si:H). By describing the electronic transport with the μ0τR products (mobility×recombination time) as a function of the Fermi level, we observed the same behaviour for both...

Université de Neuchâtel

Intrinsic microcrystalline silicon (μc-Si:H) deposited by VHF-GD (very high frequency-glow discharge): a new material for photovoltaics and optoelectronics

Shah, Arvind ; Vallat-Sauvain, Evelyne ; Torres, P. ; Meier, Johannes ; Kroll, U. ; Hof, Ch. ; Droz, C. ; Goerlitzer, M. ; Wyrsch, Nicolas ; Vaněček, M.

In: Materials Science and Engineering B, 2000, vol. 69-70, p. 219-226

The development of μc-Si:H technology and the introduction of intrinsic μc-Si:H as photovotaically active material is retraced. Special emphasis is laid on the use of very high frequency glow discharge as a particularly propitious deposition method for μc-Si:H. Thereby, the use of a gas purifier to reduce oxygen content and obtain intrinsic layers with ‘midgap’ character is described....

Université de Neuchâtel

Ambipolar diffusion length and photoconductivity measurements on ”midgap'' hydrogenated microcrystalline silicon

Goerlitzer, M. ; Beck, N. ; Torres, P. ; Meier, J. ; Wyrsch, Nicolas ; Shah, Arvind

In: Journal of Applied Physics, 1996, vol. 80, no. 9, p. 5111-5115

Hydrogenated microcrystalline silicon (µc-Si:H) deposited by VHF plasma-enhanced chemical vapor deposition has recently been proven to be fully stable, with respect to light-induced degradation, when adequately used in p-i-n solar cells. Stable solar cells efficiencies of 7.7% have been obtained with single-junction cells, using ``midgap'' microcrystalline i-layers, having...

Université de Neuchâtel

The “Micromorph” cell: a new way to high-efficiency-low-temperature crystalline silicon thin-film cell manufacturing?

Keppner, H. ; Kroll, U. ; Torres, P. ; Meier, J. ; Platz, R. ; Fischer, D. ; Beck, N. ; Dubail, S. ; Anna Selvan, J. A. ; Pellaton Vaucher, N. ; Goerlitzer, M. ; Ziegler, Y. ; Tscharner, R. ; Hof, Ch. ; Goetz, M. ; Pernet, P. ; Wyrsch, Nicolas ; Vuille, J. ; Cuperus, J. ; Shah, Arvind ; Pohl, J.

In: AIP Conference Proceeding, 1997, vol. 394, no. 1, p. 271-281

Hydrogenated microcrystalline Silicon (µc-Si:H) produced by the VHF-GD (Very High Frequency Glow Discharge) process can be considered to be a new base material for thin-film crystalline silicon solar cells. The most striking feature of such cells, in contrast to conventional amorphous silicon technology, is their stability under light-soaking. With respect to crystalline silicon technology,...