Achieving a New World Record Silicon Solar Cell Efficiency of 26.81% Using SHJ Device Structure

As the cornerstone of photovoltaitics industry, silicon solar cell draws extensive interests and its progress on conversion efficiency concerns the implementation of carbon neutrality promise. In order to achieve high efficiency, good surface passivation, low contact resistance and transparent front skin are the indispensable requirements, bringing about variety of technologies and strategies to balance out for maximum efficiency. Recently, our group achieved a new world record, 26.81%, in silicon solar cells using improved heterojunction technology (SHJ). Thanks to the successful integration of nanocrystalline doped hydrogenated silicon (nc-Si:H), surface passivation quality is further enhanced by field effect and the contact resistance is highly restrained. On the other hand, oxygen doping at front nc-Si:H broadens the band gap and the transparency to short-wavelength sunlight is increased for higher short-circuit current density. Combined with new transparent conductive oxide and advanced metallization, intrinsic properties of silicon emerge from intricate power loss mechanism, causing unprecedented fill factor and record conversion efficiency in silicon solar cells. Moreover, our record solar cell is based on front and rear contacted architecture with full-size commercial Czochralski silicon wafer and total-area certification. With the simplicity and compatibility of our SHJ technology to mass production, it is easy to transfer the result into industrial manufacture with high mass production cell conversion efficiency.