Improved electron transfer and plasmonic effect in dye-sensitized solar cells with bi-functional Nb-doped TiO₂/Ag ternary nanostructures

Abstract

TiO2 nanoparticles are surface-modified via atom transfer radical polymerization (ATRP) with a hydrophilic poly(oxyethylene)methacrylate (POEM), which can coordinate to the Ag precursor, i.e. silver trifluoromethanesulfonate (AgCF3SO3). Following the reduction of Ag ions, a Nb2O5 doping process and calcination at 450 °C, bi-functional Nb-doped TiO2/Ag ternary nanostructures are generated. The resulting nanostructures are characterized by energy-filtering transmission electron microscopy (EF-TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and UV-visible spectroscopy. The dye-sensitized solar cell (DSSC) based on the Nb-doped TiO2/Ag nanostructure photoanode with a polymerized ionic liquid (PIL) as the solid polymer electrolyte shows an overall energy conversion efficiency (η) of 6.9%, which is much higher than those of neat TiO2 (4.7%) and Nb-doped TiO2 (5.4%). The enhancement of η is mostly due to the increase of current density, attributed to the improved electron transfer properties including electron injection, collection, and plasmonic effects without the negative effects of charge recombination or problems with corrosion. These properties are supported by intensity modulated photocurrent/voltage spectroscopy (IMPS/IMVS) and incident photon-to-electron conversion efficiency (IPCE) measurements.

Multifunctional Organized Mesoporous Tin Oxide Films Templated by Graft Copolymers for Dye‐Sensitized Solar Cells

“…The electron transport and charge recombination properties of the nc‐TiO 2 layer and om‐SnO 2 IF/nc‐TiO 2 layer photoanodes were measured through IMPS and IMVS analyses. Poly{[1‐(4‐ethenylphenyl)methyl]‐3‐butylimidazolium iodide} was synthesized by free radical polymerization as a PIL and utilized as a solid electrolyte for DSSCs without using any additives such as iodide salts or iodine 27–29. The ionic conductivity of the PIL reached 2.0×10 −4 S cm −1 at room temperature as a result of the well‐ordered structures with π–π stacking interactions and a low glass transition temperature of −4 °C 28.…”

Structural color-tunable mesoporous bragg stack layers based on graft copolymer self-assembly for high-efficiency solid-state dye-sensitized solar cells

“…We also tested the functionality of structural color-tunable mesoporous BS-functionalized counter electrodes by fabricating ssDSSCs using a single-component solid polymer, namely poly((1-(4-ethenylphenyl)methyl)-3-butyl-imidazolium iodide) (PEBII). The PEBII worked well as the solid electrolyte, even without additives such as iodide salt or iodine (I 2 ) [36,45,48]. PEBII solidifies by means of radical polymerization and shows high ionic conductivity and good mechanical stability due to pep stacking interactions.…”

“…The IPCE is a product of light harvesting efficiency (h lh ), electron injection efficiency (h inj ), and electron collection efficiency (h col ). In addition, it is well known that J sc is strongly related to IPCE efficiency (h IPCE ) of the light harvesting properties [48]. The EIS Nyquist plots of the mesoporous BS counter electrode-based devices were measured from high to low frequency under one sun illumination.…”

Bandgap Engineering and Signature of Ferromagnetism in Ti1−xMnxO2­ Diluted Magnetic Semiconductor Nanoparticles: A Valence Band Study

“…The systems doped with magnetic ions (basically transition metals such as Fe, Co, Mn, Ni, Cr etc.) into the non‐magnetic matrices have attracted huge interest of many researchers in recent years due to their potential applications . The combination of magnetic and transport properties in doped semiconductor materials lead to many interesting phenomena.…”