title: Low-Temperature Thermally Reduced Molybdenum Disulfide as a Pt-Free Counter Electrode for Dye-Sensitized Solar Cells.
abstract: A two-dimensional nanostructure of molybdenum disulfide (MoS2) thin film exposed layered nanosheet was prepared by a low-temperature thermally reduced (TR) method on a fluorine-doped tin oxide (FTO) glass substrate as a platinum (Pt)-free and highly electrocatalytic counter electrode (CE) for dye-sensitized solar cells (DSSCs). Thermogravimetric analysis (TGA) results show that the MoS2 sulfidization temperature was approximately 300 °C. X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HRTEM), and X-ray diffraction (XRD) indicate that the stoichiometry and crystallization of MoS2 were more complete at higher temperatures; however, these temperatures reduce the number of edge-plane active sites in the short-range-order nanostructure. Accordingly, the DSSCs with 300 °C annealed TR-MoS2 CE exhibited an excellent photovoltaic conversion efficiency (PCE) of 6.351 %, up to 91.7 % of which is obtained using the conventional TD-Pt CE (PCE = 6.929 %). The temperature of thermal reaction and the molar ratio of reaction precursors were found to significantly influence the resulting stoichiometry and crystallization of MoS2 nanosheets, thus affecting DSSCs' performance.
authors.affiliation: Department of Engineering and System Science, National Tsing Hua University, Hsinchu, 30013, Taiwan, Republic of China. s101011517@m101.nthu.edu.tw.
authors.forename: Che-Hsien
authors.initials: CH
authors.lastname: Lin
authors.affiliation: Department of Engineering and System Science, National Tsing Hua University, Hsinchu, 30013, Taiwan, Republic of China. chuenhorng1950@gmail.com.
authors.forename: Chuen-Horng
authors.initials: CH
authors.lastname: Tsai
authors.affiliation: Department of Engineering and System Science, National Tsing Hua University, Hsinchu, 30013, Taiwan, Republic of China. fangangtseng@gmail.com.
authors.forename: Fan-Gang
authors.initials: FG
authors.lastname: Tseng
authors.affiliation: Department of Materials Engineering, Ming Chi University of Technology, 84 Gungjuan Rd., Taishan District, New Taipei City, 24301, Taiwan, Republic of China. yyyu@mail.mcut.edu.tw.
authors.forename: Yang-Yen
authors.initials: YY
authors.lastname: Yu
authors.affiliation: Department of Materials Engineering, Ming Chi University of Technology, 84 Gungjuan Rd., Taishan District, New Taipei City, 24301, Taiwan, Republic of China. hcwu@mail.mcut.edu.tw.
authors.forename: Hsuan-Chung
authors.initials: HC
authors.lastname: Wu
authors.affiliation: Department of Materials Engineering, Ming Chi University of Technology, 84 Gungjuan Rd., Taishan District, New Taipei City, 24301, Taiwan, Republic of China. jack_hsieh@mail.mcut.edu.tw.
authors.forename: Chien-Kuo
authors.initials: CK
authors.lastname: Hsieh
keywords: Counter electrode; Dye-sensitized solar cells; Molybdenum disulfide; Thermal reduction