Lab-scale vacuum equipment for HJT solar cell production

Solar cells based on a-Si:H/c-Si heterojunction (HJT) is becoming a prime candidate for future photovoltaic. The advantages and limitations of various equipment that used for the high efficiency HJT solar cell formation are discussed to analyze the perspectives of the HJT technology. Izovac Ltd. has built a progressive set of vacuum equipment for PECVD and PVD processes for single wafer treatment in cooperation with RegHer Solar LLC. We are focused on improving of silicon surface passivation and high effective p/n-junction formation and adjusting of TCO process. Due to contamination of the surface of silicon in breaking cycle together with dangling bonds from textured silicon that act as defect states, thus leading to the presence of recombination centers and traps limiting the electrical properties of the Si wafer. The designed multichamber device allowed us to passivate both sides of wafers by a single process in authomatic mode. Extremely uniform defect free layers with high carrier life time (up to 10 milliseconds) are obtained. Using of optimized sputtering system provides damage free deposition of TCO. Set of PECVD and PVD equipment allows producing 100 wafers per hour. Such approach could be easy scale to mass production.