李耀文教授在 Adv. Mater. 上发表研究论文

Reducing Energy Disorder of Hole Transport Layer by Charge Transfer Complex for High Performance p–i–n Perovskite Solar Cells

Guiying Xu1, Rongming Xue1, Samuel J. Stuard2, Harald Ade2, Chenjie Zhang1, Jianlin Yao1, Yaowen Li1, *(李耀文), and Yongfang Li1,3


1 Laboratory of Advanced Optoelectronic MaterialsCollege of Chemistry  Chemical Engineering and Materials ScienceSoochow UniversitySuzhou 215123, China

2Department of Physics and Organic and Carbon Electronic Laboratories (ORaCEL)North Carolina State UniversityRaleigh, NC 27695, USA

3Beijing National Laboratory for Molecular Sciences Institute of ChemistryChinese Academy of SciencesBeijing 100190, China


Adv. Mater. 2021, 2006753


Solutionprocessed organic semiconductor chargetransport layers (OSCTLs) with high mobility, low trap density, and energy level alignment have dominated the important progress in p–i–n planar perovskite solar cells (peroSCs). Unfortunately, their inevitable long chains result in weak molecular stacking, which is likely to generate high energy disorder and deteriorate the chargetransport ability of OSCTLs. Here, a chargetransfer complex (CTC) strategy to reduce the energy disorder in the OSCTLs by doping an organic semiconductor, 4,4′(4,8bis(5(trimethylsilyl)thiophen2yl)benzo[1,2b:4,5b′]dithiophene2,6diyl)bis(N,Nbis(4methoxyphenyl)aniline) (BDTSi), in a commercial holetransport layer (HTL), poly[bis(4phenyl) (2,4,6trimethylphenyl)amine (PTAA), is proposed. The formation of the CTC makes the PTAA conjugated backbone electrondeficient, resulting in a quinoidal and stiffer character, which is likely to planarize the PTAA backbone and enhance the ordering of the film in nanoscale. The resultant HTL exhibits a reduced energy disorder, which simultaneously promotes hole transport in the HTL, hole extraction at the interface, energy level alignment, and quasiFermi level splitting in the device. As a result, the p–i–n planar peroSCs with optimized HTL exhibit the best power conversion efficiency of 21.87% with good operating stability. This finding demonstrates that the CTC strategy is an effective way to reduce the energy disorder in HTLs and to improve the performance of planar peroSCs.



链接:https://onlinelibrary.wiley.com/doi/full/10.1002/adma.202006753