51 research outputs found
Plasma texturing for silicon solar cell: study on hybrid mono-like and on traditional multicrystalline wafers
International audienc
Improvement of Performance of Crystalline Silicon Solar Cells by the Use of Dry Polishing
International audienc
Plasma Texturing for Solar Cell: Study on Hybrid Mono-Like and on Traditional Multicrystalline Wafers
International audienc
Carrier lifetime influence on clamped silicon wafer resonance by PTA effect
This experimental work presents reproducible measurement conditions to allow
amplification of the mechanical vibration generated by
photo-thermo-acoustics (PTA) effect using the resonance of circular silicon
membranes clamped by nitrile o-rings on a diameter of 30Â mm (Di). We use
wafers with various thickness (h) between 250 and 1000 μm and with
carrier lifetime between 3 and 30 μs. Under the condition to have a
resolution of few picometers for the measurement, it is possible to
characterize the resonance mechanism obtained without contact by
conventional laser vibrometry using a modulated laser diode of only a few
milliwatts of power. Compared to perfect clamped membranes, the first Eigen
frequency presents a downward shift of some hundreds Hertz due to the
circular clamping by o-ring as predicted by our simplified model. The
resonance frequency depends linearly on the thickness as long as
Di/h > 80. The quality factor (Q) does not exceed ten in agreement with
our model for spring loaded membrane in air. The low value of quality factor
and its variation according to thickness follow our predictions. Moreover, Q
is independent of carrier lifetime whereas first resonance amplitude
increases with it but less than prediction for bulks
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