Proceedings of International Conference on Perovskite and Organic Photovoltaics and Optoelectronics (IPEROP19)
DOI: https://doi.org/10.29363/nanoge.iperop.2019.049
Publication date: 23rd October 2018
Environmental friendly Sn-based perovskite solar cells (PSCs) have emerged as one of the most promising Pb-free photovoltaic materials due to their superior photoelectric property in comparison to Pb-based perovskites. [1-3] In spite of the superior photovoltaic properties, the poor ambient and light soaking stability of Sn-based film still seriously restricts the development of Sn-based PSCs. The reason for the poor stability of Sn-based PSCs is the tendency of oxidation from Sn2+ to Sn4+ state of Sn-based film, which leads to an unwanted p-type doping and damages the suitable semiconducting photovoltaic properties of the Sn-based film. Here in this work, we proposed
an additive engineering strategy in the precursor solution of Sn-based PSCs, significantly increased the crystal quality of the Sn-based film. The high crystal quality of the Sn-based film was clarified by its surface morphology, crystallography, and optical properties. Benefiting from high crystal quality, the oxidation rate of Sn2+ to Sn4+ state of the Sn-based film was greatly slowed down. A power conversion efficiency of over 7% for our Sn-based devices can be achieved. More importantly, the unencapsulated device can maintain over 85% of its initial efficiency for 700 min in ambient, and the encapsulated device can maintain over 90% of its initial efficiency for over 800 h under continuous AM1.5 light soaking.
This work was partially supported by the New Energy and Industrial Technology Development Organization (NEDO), National Natural Science Foundation of China (11574199 and 11674219).