SPLTRAK Abstract Submission
Effects of (i)a-Si:H deposition temperature on passivation quality and performance of high-efficiency silicon heterojunction solar cells
Yifeng Zhao, Paul Procel, Arno H. M. Smets, Luana Mazzarella, Can Han, Liqi Cao, Guangtao Yang, Zhirong Yao, Arthur Weeber, Miro Zeman, Olindo Isabella
Photovoltaic Materials and Devices Group, Delft University of Technology, Delft, Netherlands

Excellent surface passivation induced by (i)a-Si:H is critical to achieve high-efficiency silicon heterojunction (SHJ) solar cells. In this study, we investigated the effects of (i)a-Si:H deposition temperature on passivation quality and solar cell performance. Among the deposition temperatures we investigated (140 - 200 °C), lower temperatures seem to result in less dense (i)a-Si:H films, which hinder their surface passivation capabilities. However, with additional hydrogen plasma treatments (HPTs), those (i)a-Si:H layers exhibited significant improvements and better passivation qualities than their higher temperature counterparts. On the other hand, even though we observed the highest VOCs for cells with (i)a-Si:H deposited at the lowest temperature (140 °C), the related FFs are poorer as compared to their higher temperature counterparts. The optimum trade-off between VOC and FF was found with temperatures ranging from 160 °C to 180 °C, which delivered independently certified efficiencies of 23.71%. Thus our study reveals two critical requirements for optimizing the (i)a-Si:H layers in high-efficiency SHJ solar cells: (i) excellent surface passivation quality to reduce losses induced by interface recombinations and (ii) less-defective (i)a-Si:H bulk to improve the charge carrier collections.