TY - JOUR
T1 - Insight into the Enhanced Charge Transport in Quasi-2D Perovskite via Fluorination of Ammonium Cations for Photovoltaic Applications
AU - Wang, Ze
AU - Liu, Xiaodong
AU - Ren, Hui
AU - Liu, Li
AU - Tang, Xinyu
AU - Yao, Xianghua
AU - Su, Zhenhuang
AU - Gao, Xingyu
AU - Wei, Qi
AU - Xie, Haijiao
AU - Zheng, Yonghao
AU - Li, Mingjie
N1 - Funding Information:
The authors gratefully acknowledge the financial support from the Hong Kong Polytechnic University (Grant Nos. 1-BE2Z, W188, and 1-ZVGH) and the Shenzhen Science, Technology and Innovation Commission (Project No. R2021A064). The open research fund of Key Laboratory for Organic Electronics and Information Displays, the National Natural Science Foundation of China (Nos. 61604101, 61805034, 61904152, and 62174112), the National Key Research and Development Program of China (No. 2019YFE0120000), and the Fundamental Research Funds for the Central Universities (No. YJ201955) are also acknowledged.
Publisher Copyright:
© 2022 American Chemical Society. All rights reserved.
PY - 2022/2/16
Y1 - 2022/2/16
N2 - Fluorinated spacer cations in quasi-2D (Q-2D) perovskites have recently been demonstrated to improve the Q-2D perovskite solar cell (PSC) performance. However, the underlying mechanism of fluorination of organic cations on the improvement is still unclear. Here, using fluorinated benzylammonium (named F-BZA) as a spacer cation in Q-2D Ruddlesden-Popper (RP) perovskites, we deeply investigate the effect of fluorination of organic cations on perovskite crystallization and intermolecular interactions for improving the charge transport and device performance. It is found that fluorination of spacer cations can slow down the crystallization rate of perovskites, resulting in vertically aligned large grains. Moreover, the interaction between the adjacent spacer cations is further enhanced, constructing a new faster charge-transport channel with a lifetime of 77 ps. Accordingly, the carrier mobility is improved by an order of magnitude and a power conversion efficiency (PCE) of 16.82% is achieved in much more stable F-BZA-based Q-2D RP PSCs, 35% higher than that of BZA-based devices (12.39%). Our results elucidate the mechanism and its importance of fluorinating spacer cations for high-performance Q-2D PSC development.
AB - Fluorinated spacer cations in quasi-2D (Q-2D) perovskites have recently been demonstrated to improve the Q-2D perovskite solar cell (PSC) performance. However, the underlying mechanism of fluorination of organic cations on the improvement is still unclear. Here, using fluorinated benzylammonium (named F-BZA) as a spacer cation in Q-2D Ruddlesden-Popper (RP) perovskites, we deeply investigate the effect of fluorination of organic cations on perovskite crystallization and intermolecular interactions for improving the charge transport and device performance. It is found that fluorination of spacer cations can slow down the crystallization rate of perovskites, resulting in vertically aligned large grains. Moreover, the interaction between the adjacent spacer cations is further enhanced, constructing a new faster charge-transport channel with a lifetime of 77 ps. Accordingly, the carrier mobility is improved by an order of magnitude and a power conversion efficiency (PCE) of 16.82% is achieved in much more stable F-BZA-based Q-2D RP PSCs, 35% higher than that of BZA-based devices (12.39%). Our results elucidate the mechanism and its importance of fluorinating spacer cations for high-performance Q-2D PSC development.
KW - charge transport
KW - charge-transfer channel
KW - fluorination of ammonium cations
KW - quasi-2D perovskite solar cells
KW - stability
UR - http://www.scopus.com/inward/record.url?scp=85124308645&partnerID=8YFLogxK
U2 - 10.1021/acsami.1c21715
DO - 10.1021/acsami.1c21715
M3 - Journal article
AN - SCOPUS:85124308645
SN - 1944-8244
VL - 14
SP - 7917
EP - 7925
JO - ACS Applied Materials and Interfaces
JF - ACS Applied Materials and Interfaces
IS - 6
ER -
