Two dimensional graphitic carbon nitride quantum dots modified perovskite solar cells and photodetectors with high performances

• Published in: Journal of power sources 2020-03, Vol.451, p.227825, Article 227825
• Main Authors: Liu, Pei, Sun, Yue, Wang, Shaofu, Zhang, Huijie, Gong, Youning, Li, Fangjie, Shi, Yunfan, Du, Yunxiao, Li, Xiaofeng, Guo, Shi-shang, Tai, Qidong, Wang, Changlei, Zhao, Xing-Zhong
• Format: Article
• Language: English
• Subjects: Air-process; Graphitic carbon nitride dots; Interfacial engineering; Perovskite solar cell; Two dimension polymeric material
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2020.227825

Two dimensional materials have promising benefits in photoelectronic devices, including facilitating charge transport and reducing defects in perovskite solar cells (PSCs) and photodetectors (PDs) through interface engineering. Herein, a two dimension polymeric material of graphitic carbon nitride quantum dots (g-CNQDs) interlayer is used to modify the SnO2/perovskite interface in both ambient PSCs and PDs to improve the overall performance. The introduction of g-CNQD layer improves the crystalline quality of sequential perovskite absorber with high phase purity, less grain boundaries, low trap states and suppressed carrier recombination due to the intrinsic cross-linkable feature and relatively smooth surface of g-CNQD. As a result, with optimal modification, fully air-processed PSC reached a champion power conversion efficiency of 21.23% with negligible hysteresis, and the PDs had remarkable performance enhancement. Moreover, our PSCs have good stability in ambient air, keeping over 90% of the initial efficiency after 30 days’ exposure. [Display omitted] •Two dimensional carbon nitride quantum dots were introduced in PSCs and PDs.•G-CNQDs were employed as modifying reagent at the SnO2/perovskite interface.•The crystalline quality of perovskite absorber with low trap states as achieved.•Our fully air-processed PSC reached a high efficiency over 21%.