Dual‐Strategy Tailoring Molecular Structures of Dopant‐Free Hole Transport Materials for Efficient and Stable Perovskite Solar Cells
摘要:
Dopant‐free hole transport materials (HTMs) are ideal materials for highly efficient and stable n‐i‐p perovskite solar cells (PSCs), but most current design strategies for tailoring the molecular structures of HTMs are limited to single strategy. Herein, four HTMs based on dithienothiophenepyrrole (DTTP) core are devised through dual‐strategy methods combining conjugate engineering and side chain engineering. DTTP‐ThSO with ester alkyl chain that can form six‐membered ring by the S⋅⋅⋅O noncovalent conformation lock with thiophene in the backbone shows good planarity, high‐quality film, matching energy level and high hole mobility, as well as strong defect passivation ability. Consequently, a remarkable power conversion efficiency (PCE) of 23.3 % with a nice long‐term stability is achieved by dopant‐free DTTP‐ThSO‐based PSCs, representing one of the highest values for un‐doped organic HTMs based PSCs. Especially, the fill factor (FF) of 82.3 % is the highest value for dopant‐free small molecular HTMs‐based n‐i‐p PSCs to date. Moreover, DTTP‐ThSO‐based devices have achieved an excellent PCE of 20.9 % in large‐area (1.01 cm2) devices. This work clearly elucidates the structure‐performance relationships of HTMs and offers a practical dual‐strategy approach to designing dopant‐free HTMs for high‐performance PSCs.
Synthesis and Structure of Fused α-Oligothiophenes with up to Seven Rings
作者:Xinnan Zhang、Adrien P. Côté、Adam J. Matzger
DOI:10.1021/ja053326m
日期:2005.8.1
α-oligothiophenes with the planarity of acenes, fully fused oligothienoacenes were synthesized and their properties compared to the nonfused α-oligothiophenes. By employing removable solubilizing groups, our synthetic methodology made it possible to efficiently prepare and purify oligothienoacenes with up to seven fusedrings. The key steps involved the halogen dance reaction and Pd-catalyzed coupling of Bu3SnSSnBu3