LiTFSI/TBP-free hole transport materials with nonlinear π-conjugation for efficient inverted perovskite solar cells. (10th February 2019)

• Record Type: Journal Article
• Authors: Liu, Na; Zong, Xueping; Wang, Zhihui; Cui, Tianqiang; Liang, Mao; Zhang, Yue; Xue, Song
• Is Part Of: Electrochimica acta. Volume 296(2019)
• Page Start: 283
• Page End: 293
• Publication Date: 2019-02-10
• Subjects: Perovskite solar cells -- Hole-transporting materials -- Dopant-free molecules -- Non-linear molecular -- Triphenylamine; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2018.11.055
• Languages: English
• ISSNs: 0013-4686

Abstract

Abstract: We have synthesized two non-linear molecules with Y-shaped (XSln847) and X-shaped (XSln1453) structures via a facile synthetic route. Comparable to an X-shaped structure, the Y-shaped structural backbone of XSln847 enables a tight molecular stacking arrangement through multiple intermolecular short contacts, which affords a nest-layer in molecules. As a result, the pristine, Y-shaped XSln847 gives higher hole-mobility and more effective photoluminescence quenching than does XSln1453. Additionally, a decreased charge recombination occurs in the XSln847-fabricated inverted perovskite solar cells. As a consequence, the device based on XSln847 affords a higher power conversion efficiency of 15.02% than does that of XSln1453 (12.65%) under standard global AM 1.5 illumination. The efficiency is further improved to 17.16% when using XSln847 doping with 2, 3, 5, 6-tetrafluoro- 7, 7, 8, 8-tetracyanoquinodimethane, which is much higher than that of the widely-used PEDOT:PSS (11.95%) when measured under the same condition. These results demonstrate that the molecular engineering of hole transport materials with non-linear structure is a promising strategy for designing efficient molecules for inverted perovskite solar cells. Graphical abstract: Image 1 Highlights: A new Y-shaped structural molecule (XSln847) is built by molecular engineering. The thermal stability, spectral and electrochemical characteristics is described. SC-XRD analysis reveals a tightly molecular arrangement stacking in XSln847. XSln847 realizes efficient hole-mobility and effective photoluminescence quenching. XSln847-based solar cell achieves much higher PCE than that of PEDOT:PSS.