Cluster-Suppressed Plasma Chemical Vapor Deposition Method for High Quality Hydrogenated Amorphous Silicon Films

We have developed a novel plasma chemical vapor deposition (PCVD) method for preparing high quality hydrogenated amorphous silicon (a-Si:H) films, which suppresses effectively growth of clusters by transporting them out of the reactor using gas flow and thermophoresis. By utilizing this cluster-suppressed PCVD method, we have demonstrated deposition of quite high quality a-Si:H films, microstructure parameter Rα of which can be reduced below 0.003. The decrease in Rα value is closely related to the decrease in cluster amount. Preliminary evaluation of fill factor (FF) of the a-Si:H Schottky solar cell of the a-Si:H films of Rα=0.057 shows the high initial value FFi=0.57 and high stabilized value after-light-soaking FFa=0.53.