Effect of Hydrocarbon Chain Length of Disubstituted Triphenyl-amine-Based Organic Dyes on Dye-Sensitized Solar Cells

Abstract

Three organic dyes incorporating a disubstituted triphenyl-amine unit as the electron donor, a thiophene moiety as the conjugated spacer, and 2-cyanoacrylic acid as the electron acceptor, have been synthesized and applied for the dye-sensitized solar cells (DSSCs). The conversion efficiencies of the DSSCs range from 4.99 to 6.04%. The influence of the hydrophobic hydrocarbon chain length of the substituent group in these dyes on the device performance in DSSCs has been investigated. It was found that the dyes with longer hydrocarbon chains gave higher photocurrents, open-circuit voltages, and efficiency values, which may derive from the higher molar absorption coefficient of metal-to-ligand charge transfer (MLCT), more appropriate localization of the frontier orbitals and longer electron lifetimes. We attribute the importance of the lengthening of the anchoring groups to the role of the dye as a better absorber for the incoming light and longer blocking layer to avoid charge recombination.b S Supporting Information. Synthesis of compounds 1aÀc, 2aÀc and 3aÀc. Absorption spectra of C1, C6, and C9 in different solvents. The computed absorption spectra of C1, C6, and C9. Selected calculated singlet excited-state transitions for C1, C6, and C9. The charge collection efficiencies of C1, C6, and C9 calculated from IMPS and IMVS. This information is available free of charge via the Internet at http://pubs.acs.org.

Effect of Molecular-Level Insulation on the Performance of a Dye-Sensitized Solar Cell: Fluorescence Studies in Solid State

“…Moreover, the reported structural modifications involved modifications on the TPA unit, such as inserting a bridge between the two phenyl rings [9], introducing bis-hexapropyltruxeneamino Electronic supplementary material The online version of this article (doi:10.1007/s10895-014-1479-8) contains supplementary material, which is available to authorized users. units [10], substituting of hydrophobic hydrocarbons [11], and adding indoline units in which the work was conducted with or without adding some coadsorbents, such as CDCA (chenodeoxycholic acid) [12]. However, the best reported overall efficiency (η) in any of these studies has never exceeded 6.39 % [12].…”

Indolizine‐Based Donors as Organic Sensitizer Components for Dye‐Sensitized Solar Cells

“…Additionally, substituents on the 5-positon of indolizine were found to give a signifi cant redshift (≈50 nm) when comparing H-substituted AH4 to OMe-substituted AH6 . The large redshifted absorptions (75-135 nm Δλ onset AH6 vs CQ1 , [ 11 ] C1 , [ 12 ] and LS1 [ 13 ] ) observed with the indolizine dye series when compared with other common donor-based dyes illustrates the strong electron donation strength of the indolizine building blocks. The molar absorptivities ranged from 1000-13 000 M −1 cm −1 with the short alkyl chain length dyes at the 3-position ( AH2 , AH3 , and AH5 ) yielding the lowest molar absorptivities.…”

“…TPAs and indolines are two of the most common DSC donors in organic dye designs that are common to nearly all organic sensitizers with greater than 10% PCE. [ 6,19 ] Indolizine donors exhibit substantially broader solution absorption spectra (narrowed optical band gap) compared with these donors (λ onset = 675 nm for AH6 vs λ onset = 540 nm for TPAbased CQ1 , [ 11 ] 590 nm for diMeO-TPA-based C1 , [ 12 ] and 600 nm for indoline-based LS1 , [ 13 ] Figure 7 ) and increased performance beyond 650 nm in DSC devices (Figure 6 ).…”

Research Progress on the Application of D-A-π-A Featured Sensitizer in the Dye Sensitized Solar Cells

“…但苯并噻唑敏化剂分子的平 面性不是很好, 不能很好地保持分子整体的共轭作用. 曹德榕课题组在之前合成的 D-π-A 结构敏化剂 32 的基 础上 [41] , 引入苯并噻唑作为附加受体得到 D-A-π-A 敏化 剂 33 [42] . 因为苯并噻唑对于共轭结构的破坏, 具有 观察苏建华的研究成果可以发现 [27] , 6 相比于 5 发 生了 13 nm 的红移, 说明噻吩并噻吩能够加强共轭.…”