Spiro‐Phenylpyrazole‐9,9′‐Thioxanthene Analogues as Hole‐Transporting Materials for Efficient Planar Perovskite Solar Cells
Abstract
Perovskite solar cells have emerged as a promising technique for low‐cost, light weight, and highly efficient photovoltaics. However, they still largely rely on 2,2′,7,7′‐tetrakis(N,N‐di‐p‐methoxyphenylamine)‐9,9′‐spirobifluorene (Spiro‐OMeTAD) to serve as hole‐transporting materials (HTMs). Here, a series of HTMs with small molecular weight is designed, which are constructed on a spiro core involving phenylpyrazole and a second heteroaromatics, i.e., xanthene (O atom), thioxanthene (S atom), and acridine (N atom). Through varying from phenylpyrazole substituted xanthene (PPyra‐XA), thioxanthene (PPyra‐TXA), to acridine (PPyra‐ACD), their optical and electrochemical properties, hole mobilities, and the photovoltaic performance are optimized. As a consequence, PPyra‐TXA based device exhibits the highest power conversion efficiency (PCE) of 18.06%, outperforming that of Spiro‐OMeTAD (16.15%), which could be attributed to the enhancement of hole mobility exerted by the thioxanthene. In addition, the dopant‐free device shows PCE of 11.7%. These results open a new direction for designing spiro‐HTMs by simple modification of chemical structures.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jun 09, 2017
- Source ID
- 10.1002/aenm.201700823
Entities
People
- Alex K.‐y. Jen
- Chu‐chen Chueh
- Yang Wang
- Yun Chi
- Zonglong Zhu
Organizations
- City University of Hong Kong
- National Science and Technology Council
- National Tsing Hua University
- Office of Naval Research
- United States Department of Energy
- University of Washington