Thermal Shock-Resistant Aluminum Nitride Improves Thermal Stability of Mixed Sn–Pb Perovskite Solar Cells

Perovskite solar cells (PSCs) are highly susceptible to ambient temperature and heat during operation, which can result in poor thermal stability of the device. Therefore, enhancing heat dissipation and reducing internal heat accumulation have emerged as critical research areas to enhance the thermal stability of devices. However, the current research mainly targets improving the heat dissipation of Pb-based PSCs, and there is a lack of comprehensive research on heat dissipation in mixed Sn–Pb PSCs. In this paper, aluminum nitride (AlN), known for high thermal shock resistance, is introduced as a heat dissipation layer, which reduces the heat accumulation between the perovskite layer and the electron transport layer to improve the efficiency and thermal stability of mixed Sn–Pb PSCs. AlN is introduced to increase the thermal conductivity of the perovskite layer and the entire device to improve the heat dissipation inside the device. The introduction of the AlN treatment layer not only mitigates the damage caused by heat accumulation but also enhances the overall stability of the device. The AlN-treated Sn–Pb PSCs display enhanced thermal stability, maintaining 89% of their initial efficiency even after being aged at 85 °C for 600 h. Furthermore, the incorporation of AlN also contributes to the improved power conversion efficiency, with a companion power conversion efficiency of 23.28% and a remarkable open-circuit voltage of 0.882 V.