S-alkylbenzothiophenium-based solid-state electrolyte for efficient quantum-dot sensitized solar cells. (December 2019)

• Record Type: Journal Article
• Authors: Wang, Yefeng; Zeng, Jing Hui; Zhao, Guangtao
• Is Part Of: Solar energy. Volume 194(2019)
• Page Start: 286
• Page End: 293
• Publication Date: 2019-12
• Subjects: Benzothiophene -- Organic ionic conductors -- Solid-state electrolyte -- Quantum-dots sensitized solar cells; Solar energy -- Periodicals; Solar engines -- Periodicals; 621.47
• DOI: 10.1016/j.solener.2019.10.047
• Languages: English
• ISSNs: 0038-092X

Abstract

Highlights: In this work, the benzothiophene structure was introduced into the organic ionic crystals (OICs) for the cost-effective small molecule organic hole transport materials. The synthesized OIC, S -methyl benzthiophenium tetrafluoroborate ([MBT]BF4 ), not only exhibits the high ionic conductivity, but also shows the good interface compatibility with the photoanode. Applying [MBT]BF4 into quantum-dot sensitized solar cell (QDSSC) as the matrix of solid-state electrolyte, the device achieves a power conversion efficiency of 5.49% which is higher than those previously reported for the solid-state QDSSCs. Abstract: Developing cost-effective solid-state electrolyte is a urgent issue and a common request for (photo) electrochemical cells. In this work, a series of organic ionic conductors based on the S -substituted benzothiophenium salts have been synthesized via a simple and low-cost method. Research on the thermal behavior, optical absorption and ionic conductivity shows that S -methylbenzothiophenium tetrafluoroborate ([MBT]BF4 ) among them have the good thermal stability, high ionic conductivity and no absorption in the visible region. And the solid-state electrolyte using [MBT]BF4 as the matrix exhibits the good interfacial compatibility with photoanode. Applying this solid-state electrolyte into the quantum-dot sensitized solar cell (QDSSCs), the device achieves an open circuit voltage of 0.71 V, a short circuit current density of 20.73 mW cm −2, and a power conversion efficiency of 5.49% which is higher than those previously reported for the solid-state QDSSCs.