Highly Efficient Solid‐State Dye‐Sensitized Solar Cells Based on Triphenylamine Dyes

Abstract

Two triphenylamine‐based metal‐free organic sensitizers, D35 with a single anchor group and M14 with two anchor groups, have been applied in dye‐sensitized solar cells (DSCs) with a solid hole transporting material or liquid iodide/triiodide based electrolyte. Using the molecular hole conductor 2,2',7,7'‐tetrakis‐(N,N‐di‐p‐methoxyphenyl‐amine)9,9'‐spirobifluorene (spiro‐OMeTAD), good overall conversion efficiencies of 4.5% for D35 and 4.4% for M14 were obtained under standard AM 1.5G illumination (100 mW cm−2). Although M14 has a higher molar extinction coefficient (by ∼ 60%) and a slightly broader absorption spectrum compared to D35, the latter performs slightly better due to longer lifetime of electrons in the TiO2, which can be attributed to differences in the molecular structure. In iodide/triiodide electrolyte‐based DSCs, D35 outperforms M14 to a much greater extent, due to a very large increase in electron lifetime. This can be explained by both the greater blocking capability of the D35 monolayer and the smaller degree of interaction of triiodide (iodine) with D35 compared to M14. The present work gives some insight into how the molecular structure of sensitizer affects the performance in solid‐state and iodide/triiodide‐based DSCs.

Photoinduced ultrafast dynamics of the triphenylamine-based organic sensitizer D35 on TiO2, ZrO2 and in acetonitrile

“…This Stokes shift in acetonitrile is larger than that in DCM (4800 cm À1 ). 9 The peaks of the S 0 -S 1 absorption transition of D35 on ZrO 2 (green) and TiO 2 (blue) are broadened and blueshifted by ca. 25 nm relative to acetonitrile.…”

High‐Temperature Solid‐State Dye‐Sensitized Solar Cells Based on Organic Ionic Plastic Crystal Electrolytes

“…The bias voltage for the impedance measurement was -0.70 V and the frequency ranged from 0.01-10 5 Hz. Device Fabrication and Characterization: [7,24,25] The cleaned FTO glass was covered at two parallel edges with an adhesive tape to control the thickness of mesoporous TiO 2 film. Two layers of TiO 2 particles were deposited onto cleaned FTO glass and used as photoelectrodes.…”

Electron Kinetics in Dye Sensitized Solar Cells Employing Anatase with (101) and (001) Facets

“…The amount of adsorbed dye D35 on the films was determined by UV-Vis absorption measurement, recorded with PerkinElmer Lambda 1050 spectrometer, using the dye's extinction coefficient, e 454 = 17 000 M À1 cm À1 [54]. The transmittance and reflectance of films for the band gap determination were measured at the same instrument.…”