Spiro-Phenylpyrazole-9,9′-Thioxanthene Analogues as Hole-Transporting Materials for Efficient Planar Perovskite Solar Cells

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalNot applicablepeer-review

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Detail(s)

Original languageEnglish
Article number1700823
Journal / PublicationAdvanced Energy Materials
Volume7
Issue number19
Early online date9 Jun 2017
Publication statusPublished - 11 Oct 2017

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.

Research Area(s)

  • hole-transporting materials (HTMs), perovskite solar cells (PVSCs), phenylpyrazole, spiro-structures, thioxanthene

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