Bipodal dyes with bichromic triphenylamine architectures for use in dye-sensitized solar cell applications

Abstract

A family of four bipodal triphenylamine-based dyes, three of which incorporate two triphenylamine (TPA) units, have been studied to understand their potential in light-harvesting applications.

Exploring Structure-Property Relationships in a Bio-Inspired Family of Bipodal and Electronically-Coupled Bistriphenylamine Dyes for Dye-Sensitized Solar Cell Applications

“…The presence of thiophene π-spacers, which generally increases the π-conjugation, causing a more significant bathochromic shift does not seem to be observed in this family, as all the low energy absorption edges tend to become negligible around 525 nm. This observation is consistent with the previous study on similar dyes [30]. Furthermore all -SMe derivatives also possess a high energy maxima at~325 nm.…”

“…L1 is a previously reported dye [52] that we use as a benchmark. In our previous report [30], distal TPA modification was restricted to -OMe, owing to its ease of synthesis and ability to red-shift the absorption profile by raising the HOMO energy of the donor. In addition, when moving the thiophene spacer to create different motifs (e.g., D-π-D-π-A) only subtle redox tuning is needed to significantly affect dye performance in these bis-TPA dyes.…”

“…Perhaps one of the most common donors used in organic DSSC dyes is the triphenylamine (TPA) moiety due to its electron rich nature, redox stability and non-planarity, which reduces intermolecular dye aggregation [21][22][23][24][25][26][27]. The structural diversity possible with TPA has afforded a number of organic dye topologies [28][29][30][31][32][33][34][35][36] and each modification can lead to a significant difference in optical and electronic properties. In a previous contribution, our group presented a family of D-π-D-π-A bichromic/bipodal dyes (two TPAs and two cyanoacetic acid anchors) and we investigated the placement (and importance) of a thiophene π-spacer [30].…”

“…The structural diversity possible with TPA has afforded a number of organic dye topologies [ 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 ] and each modification can lead to a significant difference in optical and electronic properties. In a previous contribution, our group presented a family of D-π-D-π-A bichromic/bipodal dyes (two TPAs and two cyanoacetic acid anchors) and we investigated the placement (and importance) of a thiophene π-spacer [ 30 ]. It was hypothesized that the thiophene placement could be critical for ground state electronic coupling between the TPA donors.…”

Systematic Design of Electrochromic Energy Storage Devices Based on Metal–Organic Monolayers

“…In order to increase the charging capabilities of the EESDs, the CE was modified with an electron storage layer by screen-printing a transparent film of TiO 2 anatase on the flat ITO/glass CE (Figure ). In addition, the enhanced surface area of the WE and TiO 2 /ITO/glass CE is expected to balance the non-Faradaic capacitance of two electrodes . Moreover, TiO 2 is tolerant to lithium ions; , therefore, the resulting TiO 2 /ITO/glass CE is expected to demonstrate higher cycling stability.…”