Microcrystalline Single-Junction and Micromorph Tandem Thin Film Silicon Solar Cells

Abstract

Higher open circuit voltages of the microcrystalline silicon bottom cell have a direct impact on the efficiency of the micromorph (μc-Si:H/a-Si:H) tandem cell. In this paper it is shown that open circuit voltages over 500 mV can be achieved leading to gc-Si:H cell efficiencies of 8.5 %. The behaviour of such cells is characterised both by the illuminated and the dark I-V characteristics in function of cell temperature. Microcrystalline cells with Voc-values higher than 500 mV and micromorph tandems possess in general a lower value of the temperature coefficient of the fill factor and thus of the efficiency, when compared to c-Si. Temperature-dependent dark I-V measurements suggest that the dominant recombination mechanism in lgc-Si:H cells is different from that prevailing in a-Si:H solar cells.

Material and solar cell research in microcrystalline silicon

“…the contact layers (TCO, metal contacts, substrate surface). In practice, J sc values between 22 and 30 mA/cm 2 have been reported [47][48][49] for d i ¼ 1-3 mm. Because of the relatively high conductivity of mc-Si:H, special care has to be taken, when determining J sc ; to avoid wrongly including, in the measured value of J sc ; photogenerated current laterally collected from adjoining areas of the solar cells, areas that do not lie directly under the electrode layer [50].…”

Thin film silicon solar cells for space applications: Study of proton irradiation and thermal annealing effects on the characteristics of solar cells and individual layers

“…Thin-film double-junction solar cells using amorphous silicon (a-Si:H) and microcrystalline silicon (mc-Si:H), i.e. the socalled ''micromorph'' tandem cells [3][4][5][6], are a further interesting candidate for use on satellites, but the proton radiation hardness of the microcrystalline material had so far not been thoroughly explored. The present paper intends to fill this gap, by reporting on corresponding proton irradiation tests and subsequent annealing experiments.…”

Electronic transport in hydrogenated microcrystalline silicon: similarities with amorphous silicon

“…Hydrogenated microcrystalline silicon (lc-Si:H) has been successfully incorporated as intrinsic layer in p±i±n g 8X5%, [1]) or n±i±p g 7X8%, [2]) solar cells. To achieve such a good collection in the cell, high mobility and recombination time (i.e.…”