TY - JOUR
T1 - High-efficiency, solid-state, dye-sensitized solar cells using hierarchically structured TiO2 nanofibers
AU - Hwang, Daesub
AU - Jo, Seong
AU - Kim, Dong
AU - Armel, Vanessa
AU - Macfarlane, Douglas
AU - Jang, Sung-Yeon
PY - 2011
Y1 - 2011
N2 - High-performance, room-temperature (RT), solid-state dye-sensitized solar cells (DSSCs) were fabricated using hierarchically structured TiO(2) 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 TiO(2) 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.
AB - High-performance, room-temperature (RT), solid-state dye-sensitized solar cells (DSSCs) were fabricated using hierarchically structured TiO(2) 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 TiO(2) 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.
UR - http://pubs.acs.org/doi/pdf/10.1021/am200092j
U2 - 10.1021/am200092i
DO - 10.1021/am200092i
M3 - Article
SN - 1944-8244
VL - 3
SP - 1521
EP - 1527
JO - ACS Applied Materials & Interfaces
JF - ACS Applied Materials & Interfaces
IS - 5
ER -