Performance improvement of planar silicon heterojunction solar cells via sandwich-like p-type emitters

The emitter is one of the most crucial issues to achieve high-performance silicon heterojunction (SHJ) solar cells. In this work, we study the effects of single-layer and multi-layer p-type emitters, including boron-doped hydrogenated nanocrystalline silicon (nc-Si:H) and/or boron-doped hydrogenated nanocrystalline silicon oxide (nc-SiO X :H) films, on the device performance of SHJ solar cells. The results demonstrate that the sandwich-like p-type emitters of p-nc-Si:H/p-nc-SiO X :H/p + -nc-Si:H have the potential to become an effective and efficient candidate to result in higher efficiency. The lightly boron-doped p-nc-Si:H is used to reduce the incubation layer thickness in the initial stage of growth, while the low parasitic absorption of the p-nc-SiO X :H emitter leads to an increase in short-circuit current. Moreover, a highly boron-doped p + -nc-Si:H layer is implemented on top of the p-nc-SiO X :H to get a lower series resistance ( R s ) and higher fill factor. Lastly, we achieve a champion SHJ solar cell on planar wafer with an open-circuit voltage of 678.2 mV, a short-circuit current density of 36.6 mA/cm 2 , a fill factor of 77% and a conversion efficiency of 19.11%.Kindly check and confirm the ON for the affiliation 1 and 2.We confirm the accuracy of the affiliations. Graphic abstract