DC Bias Effect on Nanocrystalline Silicon Solar Cell Deposited under a High Power High Pressure Regime

We present the effect of external DC-voltage application to substrate during preparation of nanocrystalline silicon solar cell. The deposition rate, grain size, orientation property is independent of the bias conditions, whereas the crystal volume fraction shows drastic change by applying DC-voltage. This modification results in cell performance variations. A positive bias of 20 V exhibits the highest efficiency of 7.7%, while further positive bias and any negative bias produce lower efficiencies than the one made at zero bias (~6.0%). Even if we adjust the hydrogen dilution ratio so as to optimize cell performances at several bias condition, positive 20 V still shows the maximum efficiency, suggesting that the appropriate positive bias value (~ positive 20 V) is effective in improving nc-Si:H solar cell performances