IIT Delhi develops SHJ Solar Cells with 23% Efficiency

Researchers from the Department of Energy Science and Engineering at Indian Institute of Technology Delhi have achieved a significant milestone in solar PV technology. They have developed high-efficiency silicon heterojunction (SHJ) solar cells with a power conversion efficiency exceeding 23% on a 4 cm² cell. The cells also exhibit a high fill factor of approximately 81% and a voltage of around 735 mV. SHJ technology offers better performance at high temperatures, bifacial light absorption, and uses low-temperature processes. The project began through a collaboration with BHEL India. Initially, the team used an indigenously developed PECVD system before upgrading to a state-of-the-art version. Efficiency improvements have steadily progressed from 8% to over 23%. Meanwhile, researchers globally are exploring innovative approaches to further enhance SHJ solar cell technology. A recent study by RWTH Aachen University, in collaboration with Forschungszentrum Jülich GmbH, has introduced Direct Wire Bonding (DWB) - a low-temperature interconnection method for finger-free SHJ solar cells enabling material savings and efficiency gains.