Push‐Pull Phenoxazine‐Based Sensitizers for p‐Type DSSCs: Effect of Acceptor Units on Photovoltaic Performance

Abstract

Finding new efficient p-type sensitizers for NiO photocathodes is a great challenge for the development of promising low-cost tandem dye-sensitized solar cells (DSSCs). Now, the focus of researchers investigating these cells has been to create highperformance p-type systems. With this intention, herein, the design and synthesis of six new phenoxazine-based donoracceptor (D-A)-configured organic dyes PO 1-6 was reported, comprising different acceptor moieties specially designed for the sensitization of mesoporous p-type semiconductor NiO for the construction of p-type DSSCs (p-DSSCs). This work includes structural, photophysical, thermal, electrochemical, theoretical, and photoelectrochemical studies of these dyes, including evaluation of their structure-property relationships. The optical studies revealed that PO 1-6 displayed adequate absorption and emission features in the range of 480-550 and 560-650 nm, respectively, with a bandgap in the order of 2.05-2.40 eV, and their thermodynamic parameters favored an efficient interfacial charge transfer involving NiO. Among the six new dyes, the device based on sensitizer PO 2 carrying electron-withdrawing 1,3-diethyl-2-thiobarbituric acid achieved the highest power conversion efficiency of 0.031 % (short-circuit current density = 0.89 mA cm À 2 , open-circuit voltage = 101 mV, and fill factor = 35 %). Conclusively, the study furnishes an understanding of the intricacies involved in the structural modification of phenoxazine-based sensitizers to further ameliorate the performance of the p-type DSSCs.

KuQuinones: a ten years tale of the new pentacyclic quinoid compound

“…Importantly, this is the first example in which a pentacyclic quinoid core has been employed as photoactive species in a p-DSSC. Although both J sc and η % are lower with respect to the “champions” (push–pull dyes and molecular dyads), 43–46 they are in line with other reported sensitizer, 65 such as diketopyrrolopyrrole, 36,58 carbazole, 66–68 phenoxazine, 37 bodipy, 40 squaraines, 69,70 coumarine 41 and isoindigo 71 derivatives (Fig. 10).…”

“…Sensitizers used as photoactive components in p-DSSC can be divided into metal complexes 34 and metal free organic dyes. [35][36][37][38][39][40][41][42] Among the latter, push-pull molecules (donor-pspacer-acceptor), [43][44][45][46][47][48][49][50][51][52][53][54][55][56][57] and molecular dyads (donor-acceptor) [58][59][60][61][62][63] gave the best results in terms of generated photocurrent. In the framework of the on-going research of new sensitizers, KuQ have been tested in p-DSSCs.…”

Synthesis of efficient bi-anchoring bifuran/biphenyl derivatives for dye-sensitized solar cell applications

“…Dye HB-1–8 sensitizers have narrower IPCE spectra than N3 , resulting in lower photocurrent and lower photovoltaic effectiveness. 39 The relatively higher IPCE for HB-3 in comparison to other dyes is consistent with the UV-vis absorption properties' tendency. 40 In comparison, HB-1–4 bearing a bifuran attached to various acceptor moieties exhibits a broader IPCE spectrum compared to HB-5–8 containing a biphenyl with various acceptors.…”

Unadorned Molecular Engineering of Phenoxazine-Core-Based Hole-Transport Materials for Sustainable Perovskite Solar Cells

“…The Stokes shift values were found to be in the order of HTM1 (3127 cm –1 ) < HTM2 (3614 cm –1 ) < HTM3 (3739 cm –1 ); higher Stokes shift values of the HTMs can play a significant role in the pore filling of HTMs by a light soaking post-treatment or aging. From Table , HTM3 has the highest Stokes shift value, which indicates a better pore filling and lower probability of hole recombination compared to the other HTMs; hence, it would be considered to be a superior HTM in PSCs …”