Microcrystalline silicon (muc-Si) films have been prepared by a high-density, low-temperature microwave plasma for higher throughput of p-i-n junction solar cells. The correlations among plasma state, film microstructure and photovoltaic performance are investigated as functions of deposition parameters such as axial distance Z from the quartz glass plate, pressure and flow rate ratio of H-2 to SiH4 r=Fr(H-2)/Fr(SiH4). Relatively, a high deposition rate of 13 Angstrom/s is achieved with I-(2 2 0)/I-(1 1 1) of 1.7 at r = 3 and 80 mTorr pressure. Solar cells using a muc-Si photovoltaic layer show a relatively high short circuit current, J(sc) of 18 mA/ cm(2), strongly dependent on film microstructure. The correlation among plasma state, microstructure and photovoltaic performance are discussed.