A heterojunction cell efficiency of 26.6% on P-type silicon wafers has been achieved.

The heterojunction formed at the amorphous/crystalline silicon (a-Si:H/c-Si) interface possesses unique electronic properties, suitable for silicon heterojunction (SHJ) solar cells. The integration of an ultra-thin a-Si:H passivation layer achieved a high open-circuit voltage (Voc) of 750 mV. Moreover, the a-Si:H contact layer, doped with either n-type or p-type, can crystallize into a mixed phase, reducing parasitic absorption and enhancing carrier selectivity and collection efficiency.

LONGi Green Energy Technology Co., Ltd.’s Xu Xixiang, Li Zhenguo, and others have achieved a 26.6% efficiency SHJ solar cell on P-type silicon wafers. The authors employed a phosphorus diffusion gettering pretreatment strategy and utilized nanocrystalline silicon (nc-Si:H) for carrier-selective contacts, significantly increasing the efficiency of the P-type SHJ solar cell to 26.56%, thus establishing a new performance benchmark for P-type silicon solar cells.

The authors provide a detailed discussion on the device’s process development and photovoltaic performance improvement. Finally, a power loss analysis was conducted to determine the future development path of P-type SHJ solar cell technology.