High performance plasma hydrogenation for large-grained polycrystalline silicon thin film solar cells

Polycrystalline silicon thin-film solar cells with large grains up to 1 mm wide and 10 mm long created by diode laser crystallization require an enhanced high performance plasma hydrogenation process for better cell performance. Higher process temperature, longer process time and higher plasma power (800°C, 16 minutes and 3.9 kW, respectively) than those used for smaller grain polycrystalline silicon films were applied and their effects on the cell performance were evaluated. It is found that open circuit voltage increases from 417 mV to 451 mV for 0.1-suns and from 518 mV to 529 mV for 1-sun due to lower the diode saturation currents from 3.1e-5 A/cm² to 1.2e-5 A/cm² after such a hydrogenation process. This result shows that enhanced hydrogenation has a potential for application to various polycrystalline silicon films with wide range of grain size and defect density.