In-situ SnSe deposition as passivation for scalable and stable quasi-2D lead-tin perovskite solar cells
Maria A. Loi a
a Zernike Institute for Advanced Materials, University of Groningen, Netherlands
Invited Speaker, Maria A. Loi, presentation 143
Publication date: 6th February 2024

Lead-tin (Pb-Sn) perovskites are a highly promising composition for single-junction and all-perovskite tandem solar cells due to their narrower bandgap and reduced toxicity. While the use of quasi-two-dimensional (quasi-2D) Ruddlesden-Popper phases has resulted in superior stability towards the environment and large improvement in the crystallization with respect to the 3D compositions, very little work has been done towards their deposition with scalable techniques. In my presentation, I will show that PEA2(FA0.5MA0.5)4(Pb0.5Sn0.5)5I16 (n=5) with a gradient structure is successfully prepared for the first time by a two-step blade coating. Perovskite films which are treated with tin (II) acetate (SnAc2) along with N, N-dimethylselenourea (DMS) exhibit a reduced number of surface traps and enhanced surface crystallization, owing to the in-situ formation of tin selenide (SnSe). Record devices with power conversion efficiency (PCE) of 15.06%, an open circuit voltage (VOC) of 0.855 V, and negligible hysteresis are obtained. More importantly, the hydrophobic SnSe significantly protects the active layer from the environment. These devices retain 91% of the original PCE after 10 days in ambient air (30%-40% humidity) without encapsulation, and nearly no-degradation of the PCE is detected after over a month of storage in inert atmosphere, and under continuous MPP tracking for 15 hours. At the end I will also show how it is possible to transform the fabrication process introducing less toxic solvents.

We use our own and third party cookies for analysing and measuring usage of our website to improve our services. If you continue browsing, we consider accepting its use. You can check our Cookies Policy in which you will also find how to configure your web browser for the use of cookies. More info