Numerical Simulation on Effects of TCO Work Function on Performance of a-Si:H Solar Cells

In this paper, we have investigated the effect of the work function of transparent conducting oxides (TCO) on the performance of a-Si:H p-i-n solar cells, including open circuit voltage (V OC ), short circuit current (J SC ), fill factor (FF) and conversion efficiency, using AFORS-HET software. The simulation has focused on two layers: front contact work function (Φ TCO -front) and back contact work function (Φ TCO -back) with various band from 4.7 eV to 5.3 eV and 4.2 eV to 4.9 eV respectively. From the simulation results, we know that the work function of TCO greatly affects the performance of solar cells such as Voc, Jsc, FF and conversion efficiency. By optimization, we arrive at results for V oc , J sc, FF and conversion efficiencies of 0.88 V, 8.95 mA / cm 2 , 65% and 5.1% respectively. This result is obtained on Φ TCO -front 5.2 eV. When Φ TCO -front 5.2 eV, the value of V OC , FF and conversion efficiency has been saturated, while the value of the J sc actually begins to decrease. Furthermore, when the Φ TCO - back is 4.3 eV, we get the best results for V OC , J sc , FF and conversion Efficiency of 0.9 V, 8.96 mA / cm 2 , 73 % and 5.9 % respectively. When Φ TCO -back 4.3 eV, the value of V OC , FF and conversion efficiency begins to decrease, while the value of the J sc does’t change significantly. These optimizations may help in producing low cost high efficiency p-i-n solar cells experimentally.