Interface engineering of low temperature processed all-inorganic CsPbI2Br perovskite solar cells toward PCE exceeding 14

• Published in: Nano energy Vol. 60; pp. 583 - 590
• Main Authors: Zhou, Long, Guo, Xing, Lin, Zhenhua, Ma, Jing, Su, Jie, Hu, Zhaosheng, Zhang, Chunfu, Liu, Shengzhong (Frank), Chang, Jingjing, Hao, Yue
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-06-2019
• Subjects: All-inorganic perovskites; High performance; Interfacial layer; MoO3; Solar cells; Solar cells; Interfacial layer; High performance; MoO3; All-inorganic perovskites
• ISSN: 2211-2855
• DOI: 10.1016/j.nanoen.2019.03.081

All-inorganic perovskite CsPbI2Br has received much attention recently due to its suitable bandgap and excellent thermal stability. Herein, we demonstrated a low temperature solution process to obtain high quality CsPbI2Br films and fabricate devices with a facile n-i-p structure (ITO/SnO2/CsPbI2Br/Spiro-OMeTAD/MoO3/Ag), in which MoO3 was introduced as interfacial layer that led to high efficient charge extraction and suppressed carrier recombination. As a result, the champion cells exhibited a relatively high power conversion efficiency of 14.05% and superb fill factor of 81.5%. More importantly, unencapsulated PSCs with MoO3 interfacial layers showed outstanding stabilities with retaining 80% of initial PCE with thermal treatment at 85 °C for 140 min in ambient air, 80% of initial PCE under continuous illumination for 120 min in ambient air, and 89% of initial PCE after being stored in N2 glove-box over 60 days. Meantime, it should be mentioned that all interlayers and active layer were processed at temperature below 160 °C, and hence, this fabrication technique is promising for flexible energy devices and future commercialization.
Low temperature processed high performance all-inorganic perovskite solar cells with MoO3 as interfacial layer have been achieved with PCE exceeding 14% via sequential graded thermal annealing process. Moreover, the unencapsulated device exhibited enhanced operational stability under continuously simulated sunlight illumination, thermal stability and outstanding air stability after 60 days of storage under N2 condition. [Display omitted]
•High performance with PCE of 14 % and FF of 81.5 % are achieved by using low temperature solution processed CsPbI2Br.•The MoO3 interfacial layer has been introduced to enhance charge extraction and suppressed carrier recombination.•The unencapsulated device exhibited enhanced operational stability and thermal stability.