Hwang, Daesub Jo, Seong Mu Kim, Dong Young Armel, Vanessa MacFarlane, Douglas R. Jang, Sung-Yeon 2024-01-20T17:03:53Z 2024-01-20T17:03:53Z 2021-09-02 2011-05 1944-8244 https://pubs.kist.re.kr/handle/201004/130414 High-performance, room-temperature (RT), solid-state dye-sensitized solar cells (DSSCs) were fabricated using hierarchically structured TiO2 nanofiber (HS-NF) electrodes and plastic crystal (PC)-based solid-state electrolytes. The electrospun HS-NF photoelectrodes possessed a unique morphology in which submicrometer-scale core fibers are interconnected and the nanorods are dendrited onto the fibers. This nanorod-in-nanofiber morphology yielded porosity at both the mesopore and macropore level. The macropores, steming from the interfiber space, afforded high pore volumes to facilitate the infiltration of the PC electrolytes, whereas the mesoporous nanorod dendrites offered high surface area for enhanced dye loading. The solid-state DSSCs using HS-NFs (DSSC-NF) demonstrated improved power conversion efficiency (PCE) compared to conventional TiO2 nanoparticle (NP) based DSSCs (DSSC-NP). The improved performance (>2-fold) of the DSSC-NFs was due to the reduced internal series resistance (R,) and the enhanced charge recombination lifetime (tau(r)) determined by electrochemical impedance spectroscopy and intensity modulated photocurrent/photovoltage spectroscopy. The easy penetration of the PC electrolytes into HS-NF layers via the macropores reduces R-s significantly, improving the fill factor (FF) of the resulting DSSC-NFs. The tau(r) difference between the DSSC-NF and DSSC-NP in the PC electrolytes was extraordinary (similar to 14 times) compared to reported results in conventional organic liquid electrolytes. The optimized PCE of DSSC-NF using the PC electrolytes was 6.54, 7.69, and 7.93% at the light intensity of 100, 50, and 30 mW cm(-2), respectively, with increased charge collection efficiency (>40%). This is the best performing RT solid-state DSSC using a PC electrolyte. Considering the fact that most reported quasi-solid state or nonvolatile electrolytes require higher iodine contents for efficient ion transport, our HS-NFs are a promising morphology for such electrolytes that have limited ion mass transport. English American Chemical Society High-Efficiency, Solid-State, Dye-Sensitized Solar Cells Using Hierarchically Structured TiO2 Nanofibers Article 10.1021/am200092j 1 ACS Applied Materials & Interfaces, v.3, no.5, pp.1521 - 1527 ACS Applied Materials & Interfaces 3 5 1521 1527 N scie scopus 000290843800022 2-s2.0-84862833572 Nanoscience & Nanotechnology Materials Science, Multidisciplinary Science & Technology - Other Topics Materials Science Article PLASTIC-CRYSTAL ELECTROLYTE CHARGE RECOMBINATION REDOX ELECTROLYTE GEL ELECTROLYTE TRANSPORT ABSORPTION IODINE FILMS dye-sensitized solar cells TiO2 nanofibers solid-state electrolytes plastic crystal charge recombination