TY - JOUR
T1 - Complementary self-assembled monolayers enabling improved energy level alignment in inverted perovskite solar cells
AU - Zhang, Shantao
AU - Jiang, Xiaofen
AU - Wang, Xue
AU - Gao, Yan
AU - Hou, TianAo
AU - Teng, Xiaoqian
AU - Wang, Haolin
AU - Chen, Wenjing
AU - Gao, Shuang
AU - Li, Xinyu
AU - Hu, Ziqi
AU - Wu, Xiaojun
AU - Xiao, Zhengguo
AU - Chen, Tao
AU - Zhu, Yanwu
AU - Lu, Yalin
AU - Zeng, Xiaocheng
AU - Zhu, Zonglong
AU - Yang, Shangfeng
PY - 2025/5
Y1 - 2025/5
N2 - Self-assembled monolayers (SAMs) have been commonly employed as hole-selective layers (HSLs) in inverted (p-i-n) perovskite solar cells (PSCs), and typically only a single-component SAM is applied, which plays limited role in selective hole transport. Herein, we synthesize a novel SAM, (4-(3,11-dibromo-7H-dibenzo[c,g]carbazol-7-yl)butyl)phosphonic acid (Br-4PADBC), and apply it as a complementary component to the commonly used [2-(3,6-dimeth oxy-9H-carbazol-9-yl)ethyl]phosphonic acid (MeO-2PACz) SAM, accomplishing boosted hole transport in inverted PSCs. A series of characterizations and theoretical calculations are employed to unravel the roles of each components within the binary SAM (bi-SAM). The involvements of the non-planar dibenzo[c,g]carbazole unit and electron-withdrawing Br atoms induce larger dipole moment of Br-4PADBC than MeO-2PACz, resulting in much deeper work function of ITO and consequently improved alignment with the valence band energy level of perovskite. Besides, the introduced Br atoms improve the quality of perovskite crystals and help passivate defects of perovskite. On the other hand, the existence of the conventional MeO-2PACz SAM ensures the considerable conductivity of the bi-SAM and thus efficient hole extraction from the perovskite layer. As a result, inverted PSC devices based on bi-SAM HSL deliver a decent power conversion efficiency (PCE) of 24.52% as well as dramatically improved thermal and operational stabilities. © 2025 Science Press.
AB - Self-assembled monolayers (SAMs) have been commonly employed as hole-selective layers (HSLs) in inverted (p-i-n) perovskite solar cells (PSCs), and typically only a single-component SAM is applied, which plays limited role in selective hole transport. Herein, we synthesize a novel SAM, (4-(3,11-dibromo-7H-dibenzo[c,g]carbazol-7-yl)butyl)phosphonic acid (Br-4PADBC), and apply it as a complementary component to the commonly used [2-(3,6-dimeth oxy-9H-carbazol-9-yl)ethyl]phosphonic acid (MeO-2PACz) SAM, accomplishing boosted hole transport in inverted PSCs. A series of characterizations and theoretical calculations are employed to unravel the roles of each components within the binary SAM (bi-SAM). The involvements of the non-planar dibenzo[c,g]carbazole unit and electron-withdrawing Br atoms induce larger dipole moment of Br-4PADBC than MeO-2PACz, resulting in much deeper work function of ITO and consequently improved alignment with the valence band energy level of perovskite. Besides, the introduced Br atoms improve the quality of perovskite crystals and help passivate defects of perovskite. On the other hand, the existence of the conventional MeO-2PACz SAM ensures the considerable conductivity of the bi-SAM and thus efficient hole extraction from the perovskite layer. As a result, inverted PSC devices based on bi-SAM HSL deliver a decent power conversion efficiency (PCE) of 24.52% as well as dramatically improved thermal and operational stabilities. © 2025 Science Press.
KW - Dibenzo[c,g]carbazole
KW - Dipole moment
KW - Hole-selective layer
KW - Perovskite solar cells
KW - Self-assembled monolayer
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UR - https://www.scopus.com/record/pubmetrics.uri?eid=2-s2.0-85215538363&origin=recordpage
U2 - 10.1016/j.jechem.2024.12.040
DO - 10.1016/j.jechem.2024.12.040
M3 - RGC 21 - Publication in refereed journal
SN - 2095-4956
VL - 104
SP - 136
EP - 145
JO - Journal of Energy Chemistry
JF - Journal of Energy Chemistry
ER -
