Photoelectrochemical Solar Cells based on Polyterthiophenes Containing Porphyrins using Ionic Liquid Electrolyte

Inherently Conducting Polymers via Electropolymerization for Energy Conversion and Storage

“…This was largely due to improvement in V oc values (260 mV for P(TTh) 0 /Erio − /BG + compared to 134 mV for P(TTh) 0 ), while photocurrent action spectra revealed the contribution of both Erio − and BG + to the output photocurrent. The success of this approach was measured in terms of the η value of 0.11% achieved for PECs based on electrodeposited P(TTh) 0 /Erio − /BG + , which was comparable to the η value of 0.12% reported for PECs based on more complicated, electrodeposited copolymers of a porphyrin-linked bis-TTh and TTh [52,53]. Finally, the approach of Wallace and coworkers was also utilized to incorporate the anionic dye sulforhodamine-B (S-B) during the electropolymerization of TTh [56].…”

“…Copolymers were considered since homopolymers of the porphyrin-linked bis-TTh were difficult to electrodeposit due to the steric bulk of the porphyrin moiety. An overall η value of 0.12% under 50 mW cm −2 white-light illumination was achieved both for devices utilizing a Zn-coordinated porphyrin moiety with a CH 3 CN-based electrolyte [52], and a Cu-coordinated porphyrin moiety with an ionic liquid-based electrolyte [53]. Significantly, the PV properties of electrodeposited PThs with a covalently attached porphyrin moiety were improved compared to those of optimized P(TTh) without any added light-harvesting functionality reported soon after [54].…”

“…Compared to the relatively poor PV properties of P(BTh), P(TTh) has demonstrated more promising results as described below. P(TTh) has been the benchmark material in the investigations of Wallace and coworkers regarding the application of electropolymerization to energy conversion [35,38,[51][52][53][54][55][56]. In all of these investigations, the PV performance of P(TTh)-based PECs has been used as a reference to which the effect of the incorporation of electron-withdrawing and light-harvesting moieties has been measured (discussed later).…”

“…Later efforts aimed at combining the known benefit to PV properties afforded by the formation of cross-linked PThs demonstrated previously [38], and the projected benefit of covalent attachment of porphyrin light-harvesters to the PTh backbone. In this way, copolymers between TTh and a porphyrin-linked bis-TTh (Figure 11.5c) were coelectropolymerized and utilized in liquid PECs employing the I 3 − /I − redox couple [52,53]. Copolymers were considered since homopolymers of the porphyrin-linked bis-TTh were difficult to electrodeposit due to the steric bulk of the porphyrin moiety.…”

Conducting Polymers

“…This is an adequate concentration for the electrosynthesis of coherent poly(terthiophene) films onto either small Pt working electrodes, for electrochemical analysis, or onto ITO glass of a few square centimeters for analysis by UV-Vis and any photovoltaic testing required [75]. In the growth CVs of poly(terthiophene) in these ionic liquids (Figure 7.10) the influence of the nature of the ionic liquid on the growth rate of the polymer films is again evident, with significantly faster growth in the imidazolium species, and proportionally larger redox currents in the post-polymerization CVs (Figure 7.10 (b,d)).…”