A facile solution-based aluminum oxide interface layer for enhancing the efficiency and stability of perovskite solar cells

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Vol. 12; no. 21; pp. 12777 - 12784
• Main Authors: Jiao, Xinning, Ma, Guoqing, Gu, Wei-Min, Jiang, Ke-Jian, Xue, Tangyue, Yu, Guanghui, Wu, Limei, Zhang, Qing-Wu, Gao, Cai-Yan, Fan, Xin-Heng, Yang, Lian-Ming, Song, Yanlin
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 28.05.2024
• Subjects: Aluminum; Aluminum oxide; Charge transport; Efficiency; Energy conversion efficiency; Fabrication; Incompatibility; Maximum power tracking; Perovskites; Photovoltaic cells; Solar cells; Thermal stability
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/d4ta01074d

Hybrid organic-inorganic perovskites have emerged as very attractive light absorbers for the fabrication of low-cost and high-efficiency solar cells. However, their practical applications could be hindered due to their poor environmental stability and chemical incompatibility with charge transport layers and relevant electrodes in the devices. Herein, an ultrathin aluminum oxide (Al 2 O 3 ) interface layer is constructed on the surfaces of perovskite films through in situ hydrolysis and condensation of aluminum triisopropoxide (ATIP) processed by a solution-processing method under ambient conditions. The Al 2 O 3 layer is uniform and robust and can stabilize the perovskite film without affecting the charge transfer in the devices. Consequently, the constructed PSC exhibits a power conversion efficiency (PCE) of 23.52%, which presents the highest record reported so far for the Al 2 O 3 -based PSCs with the same configuration. More importantly, the Al 2 O 3 incorporation leads to a significant improvement in the device stability: the PSC without encapsulation presents high operational stability with 90% of the initial efficiency after continuous maximum power point tracking over 1000 hours, and good thermal stability with 94% of the initial efficiency after aging at 60 °C in a N 2 atmosphere for 300 hours. An ultrathin Al 2 O 3 layer is modified on a perovskite surface via in situ hydrolysis and condensation of aluminum triisopropoxide. The Al 2 O 3 layer can prevent moisture ingress, reduce the defect concentration, and suppress iodine migration in the devices.