Drastic influence of substituent position on orientation of 2D layers enables efficient and stable 3D/2D perovskite solar cells

• Published in: Cell reports physical science Vol. 4; no. 5; p. 101380
• Main Authors: Gunes, Ummugulsum, Yaylali, Figen Varlioglu, Gozukara Karabag, Zeynep, Gao, Xiao-Xin, Syzgantseva, Olga A., Karabag, Aliekber, Yildirim, Gulsevim Bensu, Tsoi, Konstantin, Shibayama, Naoyuki, Kanda, Hiroyuki, Rafieh, Alwani Imanah, Zhong, Liping, Züttel, Andreas, Dyson, Paul Joseph, Yerci, Selcuk, Nazeeruddin, Mohammad Khaja, Gunbas, Gorkem
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 17.05.2023
• Subjects: 3D/2D perovskite solar cells; novel organic 2D cations; stability; tunneling effect; novel organic 2D cations; 3D/2D perovskite solar cells; tunneling effect; stability
• ISSN: 2666-3864; 2666-3864
• DOI: 10.1016/j.xcrp.2023.101380

The lack of long-term stability and reproducibility of perovskite solar cells (PSCs) is the main roadblock preventing their successful commercialization. 3D/2D PSCs are one of the most prominent ways to address these issues. Various salts that are mostly based on phenyl ethyl ammonium iodide (PEAI) have been utilized to grow a 2D perovskite layer on 3D perovskites. Herein, we report the effect of substituting the methoxy (-OMe) group at the ortho (o), meta (m), and para (p) positions on PEAI salts. Photoluminescence and time-resolved photoluminescence show that o-OMe-PEAI-treated surfaces achieve reduced defect densities and nonradiative recombination rates compared with the other analogs. Devices with PCEs over 23% are achieved for o-OMe-PEAI-based 3D/2D PSCs, and the enhanced performance is attributed to the favorable formation energy and desired vertical orientation according to the density functional theory (DFT) analyses. Finally, the unique orientation of the o-OMe-PEAI-based 2D perovskite results in significantly enhanced long-term, moisture, and thermal stability. [Display omitted] •Effect of substituent position at PEAI-based cations on performance is revealed•PCEs over 23% with VOC (1.12 V) and FF (80.6%) are demonstrated•Retains over 95% initial efficiency after 900 h under continuous illumination•Desired vertical orientation with stable 4H phase for o-OMe-PEAI is determined by DFT The long-term stability and reproducibility issues of perovskite solar cells (PSCs) hinder their successful commercialization. 3D/2D PSCs are one of the most prominent ways to address these issues. Gunes et al. demonstrate that the position of substitution on 2D-forming cations has a profound effect on the performance and stability of the resulting devices.