Université de Neuchâtel

Potential of VHF-plasmas for low-cost production of a-Si: H solar cells

Kroll, U. ; Shah, Arvind ; Keppner, Herbert ; Meier, Johannes ; Torres, Pedro ; Fischer, D.

In: Solar Energy Materials and Solar Cells, 1997, vol. 48, no. 1-4, p. 343-350

Compared to the use of the standard glow discharge technique the production of amorphous silicon solar cells by the very high frequency glow discharge (VHF-GD) bears yet additional cost reduction potentials: Using VHF-GD at excitation frequencies higher than 13.56 MHz, a more efficient dissociation of silane gas is obtained; thus, higher deposition rates are achieved; this reduces...

Université de Neuchâtel

Towards high-efficiency thin-film silicon solar cells with the “micromorph” concept

Meier, Johannes ; Dubail, S. ; Platz, R. ; Torres, Pedro ; Kroll, U. ; Anna Selvan, J. A. ; Pellaton Vaucher, N. ; Hof, Ch. ; Fischer, D. ; Keppner, Herbert ; Flückiger, R. ; Shah, Arvind ; Shklover, V. ; Ufert, K. -D.

In: Solar Energy Materials and Solar Cells, 1997, vol. 49, no. 1-4, p. 35-44

Tandem solar cells with a microcrystalline silicon bottom cell (1 eV gap) and an amorphous-silicon top cell (1.7 eV gap) have recently been introduced by the authors; they were designated as “micromorph” tandem cells. As of now, stabilised efficiencies of 11.2% have been achieved for micromorph tandem cells, whereas a 10.7% cell is confirmed by ISE Freiburg. Micromorph cells show a rather low...

Université de Neuchâtel

Controlled nucleation of thin microcrystalline layers for the recombination junction in a-Si stacked cells

Pellaton Vaucher, N. ; Rech, B. ; Fischer, D. ; Dubail, S. ; Goetz, M. ; Keppner, Herbert ; Wyrsch, Nicolas ; Beneking, C. ; Hadjadj, O. ; Shklover, V. ; Shah, Arvind

In: Solar Energy Materials and Solar Cells, 1997, vol. 49, no. 1-4, p. 27-33

In high-efficiency a-Si : H based stacked cells, at least one of the two layers that form the internal n/p junction has preferentially to be microcrystalline so as to obtain sufficient recombination at the junction [1–6]. The crucial point is the nucleation of a very thin μc-Si : H layer on an amorphous (i-layer) substrate [2, 4]. In this study, fast nucleation is induced through the treatment...

Université de Neuchâtel

Microcrystalline/micromorph silicon thin-film solar cells prepared by VHF-GD technique

Meier, Johannes ; Vallat-Sauvain, Evelyne ; Dubail, S. ; Kroll, U. ; Dubail, J. ; Golay, S. ; Feitknecht, Luc ; Torres, Pedro ; Faÿ, Sylvie ; Fischer, D. ; Shah, Arvind

In: Solar Energy Materials and Solar Cells, 2001, vol. 66, no. 1-4, p. 73-84

Hydrogenated microcrystalline silicon prepared at low temperatures by the glow discharge technique is examined here with respect to its role as a new thin-film photovoltaic absorber material. XRD and TEM characterisations reveal that microcrystalline silicon is a semiconductor with a very complex morphology. Microcrystalline p–i–n cells with open-circuit voltages of up to 560–580 mV could...

Université de Neuchâtel

Analysis of the inner collection efficiency in hybrid silicon solar cells

Nubile, P. ; Torres, P. ; Hof, Ch. ; Fischer, D.

In: Solid-State Electronics, 1997, vol. 41, no. 8, p. 1202-1206

The collection of photogenerated carriers in hybrid silicon solar cells structures were determined by the DICE (dynamic inner collection efficiency) technique. The hybrid solar cells have a microcrystalline n-type emitter and a crystalline p-type base. Cells with amorphous buffers of several thickness and p+ back surface field microcrystalline layers were also...

Université de Neuchâtel

Compensation of the dangling-bond space charge in amorphous silicon solar cells by graded low-level doping in the intrinsic layer

Fischer, D. ; Shah, Arvind

In: Applied Physics Letters, 1994, vol. 65, no. 8, p. 986-988

The compensation of the dangling-bond space charge in amorphous silicon p-i-n solar cells by graded, low-level doping in the intrinsic layer is discussed and demonstrated experimentally. Carrier collection in p-i-n cells without doping indicates that the degraded state space charge is largely positive, and thus that boron doping should be beneficial. Solar cells with linearly...

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,...

Université de Neuchâtel

Microcrystalline silicon and micromorph tandem solar cells

Keppner, H. ; Meier, Johannes ; Torres, P. ; Fischer, D. ; Shah, A.

In: Applied Physics A: Materials Science & Processing, 1999, vol. 69, no. 2, p. 169-177

“Micromorph” tandem solar cells consisting of a microcrystalline silicon bottom cell and an amorphous silicon top cell are considered as one of the most promising new thin-film silicon solar-cell concepts. Their promise lies in the hope of simultaneously achieving high conversion efficiencies at relatively low manufacturing costs. The concept was introduced by IMT Neuchâtel, based on the...