Molecular engineering of triphenylamine‐based metal‐free organic dyes for dye‐sensitized solar cells

Abstract

In this study, the photovoltaic properties of the organic dyes based on triphenylamine having a D-π-A structure including TC201, TC202, TC203, TC601, H-P, F-P, FF-P, T-F, and P1B were investigated theoretically. In this model, triphenylamine was used as an electron donor, cyanoacrylic acid, and benzoic acid as the electron acceptors, and anthracene phenyl, anthracene vinyl phenyl, anthracene ethynyl phenyl, ethynyl anthracene phenyl, styryl phenyl, styryl-2-fluorophenyl, styryl-2,6-difluorophenyl, styryl furan, and styryl as the π-conjugated systems. The results show that a change in the π-conjugated system and electron acceptor affect the properties of the dyesensitized solar cell (DSSC). Also, TC601 dye having the ethynyl anthracene phenyl π-conjugated system shows the highest charge transfer distance (D CT) and the least overlap of the electron-hole distribution (S) in comparison with other dyes. Moreover, the presence of a triple bond in the vicinity of triphenylamine increases the resonance effect of the π-electrons that facilitates the process of charge transfer in this dye. Spectroscopic analysis shows that H-P and F-P dyes have the higher molecular absorption coefficients and TC202, TC203, F-P, and T-F dyes show a red shift in comparison with other dyes. Moreover, the voltage-current curve of the studied dyes shows that the highest values of the open circuit voltage and short circuit current density are related to P1B and TC601 dyes, respectively. Finally, TC601 and P1B are proposed as the best candidates to be used in the DSSCs due to their maximum incident photon to current conversion efficiency.

Recent Advances in Monocomponent Visible Light Photoinitiating Systems Based on Sulfonium Salts

“…Triphenylamine is an interesting scaffold for the design of visible light photoinitiators due to its excellent light absorption properties in the near-UV/visible range [243,244]. Dyes of high molar extinction coefficients can also be designed with this group [245][246][247][248]. The first triphenylamine-based sulfonium salt used as a two-photon-activatable photoacid generator BSB-S2 was reported as recent as 2002 by Marder and coworkers (see Figure 8) [249].…”