C≡N-based carbazole-arylamine hole transporting materials for perovskite solar cells: Substitution position matters  

作　　者：Zi'an Zhou Xianfu Zhang Rahim Ghadari Xuepeng Liu Wenjun Wang Yong Ding Molang Cai Jia Hong Pan Songyuan Dai 

机构地区：[1]Beijing Key Laboratory of Novel Thin-Film Solar Cells,North China Electric Power University,Beijing 102206,China [2]Computational Chemistry Laboratory,Department of Organic and Biochemistry,Faculty of Chemistry,University of Tabriz,Tabriz 5166616471,Iran

出　　处：《Journal of Energy Chemistry》2021年第11期563-571,I0013,共10页能源化学（英文版）

基　　金：Zi'an Zhou and Xianfu Zhang contributed equally to this work.This work was supported by the National Key R&D Program ofChina(2018YFB1500101);the 111 Project(No.B16016);the National Natural Science Foundation of China(No.61904053,51702096,U1705256 and 51961165106);the FundamentalResearch Funds for the Central Universities(No.2019MSO_(2)6.2019MS027,and 2020MS080)。

摘　　要：Hole transporting materials(HTMs)containing passivating groups for perovskite materials have attracted much attention for efficient and stable perovskite solar cells(PSCs).Among them,C≡N-based molecules have been proved as efficient HTMs.Herein,a series of novel C≡N functionalized carbazole-arylamine derivatives with variable C≡N substitution positions(para,meta,and ortho)on benzene-carbazole skeleton(on the adjacent benzene of carbazole)were synthesized(p-HTM,m-HTM and o-HTM).The experimental results exhibit that the substitution positions of the Ctriple bondN unit on HTMs have minor difference on the HOMO energy level and hydrophobicity.m-HTM has a relatively lower glass transition temperature compared with that of p-HTM and o-HTM.The functional theory calculations show that the C≡N located on meta position exposed very well,and the exposure direction is also the same with the methoxy.Upon applying these molecules as HTMs in PSCs,their device performance is found to sensitively depend on the substitution position of the C≡N unit on the molecule skeleton.The devices using m-HTM and o-HTM exhibit better performance than that of p-HTM.Moreover,m-HTM-based devices exhibit better light-soaking performance and long-term stability,which could be resulted from better interaction with the perovskite according to DFT results.Moreover,we further prepared a HTM with two C≡N units on the symmetrical meta position of molecular skeleton(2m-HTM).Interestingly,2m-HTM-based devices exhibit relatively inferior performance compared with that of the m-HTM,which could be resulted from weak negative electrical character of C≡N unit on 2m-HTM.The results give some new insights for designing ideal HTM for efficient and stable PSCs.

关 键 词：Hole transporting materials Cyano group Substitution position Perovskite solar cells 

分 类 号：TM914.4[电气工程—电力电子与电力传动] TB34[一般工业技术—材料科学与工程]