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Rational Design of Dopant‐Free Coplanar D‐π‐D Hole‐Transporting Materials for High‐Performance Perovskite Solar Cells with Fill Factor Exceeding 80%
Author(s) -
Chen Yatong,
Xu Xiuwen,
Cai Ning,
Qian Sainan,
Luo Ruixi,
Huo Yanping,
Tsang SaiWing
Publication year - 2019
Publication title -
advanced energy materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.08
H-Index - 220
eISSN - 1614-6840
pISSN - 1614-6832
DOI - 10.1002/aenm.201901268
Subject(s) - materials science , dopant , perovskite (structure) , energy conversion efficiency , crystallography , diffraction , doping , optoelectronics , optics , physics , chemistry
In this paper, two novel D‐π‐D hole‐transporting materials (HTM) are reported, abbreviated as BDT‐PTZ and BDT‐POZ , which consist of 4,8‐di(hexylthio)‐benzo[1,2‐ b :4,5‐ b ′]dithiophene (BDT) as π‐conjugated linker, and N ‐(6‐bromohexyl) phenothiazine (PTZ)/ N ‐(6‐bromohexyl) phenoxazine (POZ) as donor units. The above two HTMs are deployed in p‐i‐n perovskite solar cells (PSCs) as dopant‐free HT layers, exhibiting excellent power conversion efficiencies of 18.26% and 19.16%, respectively. Particularly, BDT‐POZ demonstrates a superior fill factor of 81.7%, which is consistent with its more efficient hole extraction and transport verified via steady‐state/transient fluorescence spectra and space‐charge‐limited current technique. Single‐crystal X‐ray diffraction characterization implies these two molecules present diverse packing tendencies, which may account for various interfacial hole‐transport ability in PSCs.