High-Efficiency Dye-Sensitized Solar Cells: The Influence of Lithium Ions on Exciton Dissociation, Charge Recombination, and Surface States

Abstract

We present a time-saving staining protocol based upon the low-toxicity and nonvolatile solvent dimethyl sulfoxide for a high-efficiency dye-sensitized solar cell, which is very critical for the roll-to-roll flexible cell production. Power conversion efficiencies of 11.7-12.1% were achieved under AM1.5G simulated sunlights. The intrinsic roles of lithium cations on efficiency enhancement were scrutinized by measuring transient absorption and electrical impedance spectroscopies. Our studies have revealed that lithium ions can enhance exciton dissociation at the energy-offset dye/titania interface effectively. Charge collection is not found to be a crucial current loss channel in our high-efficiency dye-sensitized solar cell.

Voltage enhancement in dye-sensitized solar cell using (001)-oriented anatase TiO2 nanosheets

“…It is further illustrated by higher η values for higher light intensity. Usually, we observe opposite trends [30], but there are also examples when η and light intensity do not scale monotonically for dyes of this type [40]. Furthermore, there is no proportionality between the efficiency, η, and Г dye (Table 1).…”

Unravelling the Potential for Dithienopyrrole Sensitizers in Dye-Sensitized Solar Cells

“…1 The basic working principle, which relies on a delicate energetic balance between the anode, sensitizer, and electrolyte, is comprehensively described in a review by Hagfeldt et al 2 The most efficient cells are based on relatively expensive or synthetically challenging ruthenium(II) and porphyrin sensitizers that have provided efficiencies up to 11.7% and 11.9%, respectively. 3,4 More accessible organic dyes take the form of a D−π−A structure, which is reminiscent of push−pull chromophores used in nonlinear optics. 5 In this context, oligothiophenes and their fused derivatives are intensively exploited as π-bridges.…”

“…2 2 2 g , 2 . 3 1 m m o l ) , t r i s -(dibenzylideneacetone)dipalladium (Pd 2 (dba) 3 , 0.018 g, 0.019 mmol), and 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (BINAP, 0.048 g, 0.077 mmol) in dry toluene (1.5 mL) was purged with nitrogen. After 20 min, tridecan-7-amine (0.154 g, 0.771 mmol) was added, and the mixture was stirred overnight at 120°C.…”

Cation Exchange at Semiconducting Oxide Surfaces: Origin of Light-Induced Performance Increases in Porphyrin Dye-Sensitized Solar Cells

“…The solar-to-electric power conversion efficiencies of DSSCs depend on a balance of the kinetics for charge injection, collection, recombination and dye regeneration processes, 4 with the best devices currently exhibiting power conversion efficiencies of 11-12 % under AM 1.5 illumination. [5][6][7][8] The efficient light harvesting potential of porphyrins, exemplified by their primary role in photosynthesis, makes them promising candidates for photosensitizers within DSSCs. 7,9 Their synthesis is relatively straightforward, and their optical and electronic properties can be easily tuned via chemical modification of the porphyrin core, 10 the number of porphyrin units, 11,12 and the linker between the core and the inorganic oxide.…”