The effect of interposing nanocrystalline Si(B) P plus layer on the photovoltaic properties of a-Si: H tandem solar cells

Tandem amorphous silicon solar cells have attracted extensive interest because of better performance than single junction counterpart. as n/p junctions play an important role in the current transportation of tandem solar cells, it is important to design and fabricate good n/p junctions.the properties of the n/p junction of amorphous silicon (a-si) were studied. we investigate the effect of interposing a nanocrystalline p(+) layer between n (top cell) and p (bottom cell) layers of a tandem solar cell. the crystalline volume fraction, the band gap, the conductivity and the grain size of the nanocrystalline silicon (nc-si) p(+) layer could be modulated by changing the deposition parameters.current transport in a-si based n/p ("tunnel") junctions was investigated by current-voltage measurements. the voltage dependence on the resistance (v/j) of the tandem cells was examined to see if n/p junction was ohmic contact. to study the affection of different doping concentration to the properties of the nc-si p(+) layers which varied the properties of the tunnel junctions, three nc-si p(+) film samples were grown, measured and analyzed.