Synthesis of innovative triphenylamine-functionalized organic photosensitizers outperformed the benchmark dye N719 for high-efficiency dye-sensitized solar cells

Abstract

Herein, we present a thorough photovoltaic investigation of four triphenylamine organic sensitizers with D–π–A configurations and compare their photovoltaic performances to the conventional ruthenium-based sensitizer N719. SFA-5–8 are synthesized and utilized as sensitizers for dye-sensitized solar cell (DSSC) applications. The effects of the donor unit (triphenylamine), π-conjugation bridge (thiophene ring), and various acceptors (phenylacetonitrile and 2-cyanoacetamide derivatives) were investigated. Moreover, this was asserted by profound calculations of HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital) energy levels, the molecular electrostatic potential (MEP), and natural bond orbital (NBO) that had been studied for the TPA-sensitizers. Theoretical density functional theory (DFT) was performed to study the distribution of electron density between donor and acceptor moieties. The sensitization by the absorption of sensitizers SFA-5–8 leads to an obvious enhancement in the visible light absorption (300–750 nm) as well as a higher photovoltaic efficiency in the range of (5.53–7.56%). Under optimized conditions, SFA-7 showed outstanding sensitization of nanocrystalline TiO2, resulting in enhancing the visible light absorption and upgrading the power conversion efficiency (PCE) to approximately 7.56% over that reported for the N719 (7.29%). Remarkably, SFA-7 outperformed N719 by 4% in the total conversion efficiency. Significantly, the superior performance of SFA-7 could be mainly ascribed to the higher short-circuit photocurrents (Jsc) in parallel with larger open-circuit voltages (Voc) and more importantly, the presence of different anchoring moieties that could enhance the ability to fill the gaps on the surface of the TiO2 semiconductor. That could be largely reflected in the overall enhancement in the device efficiency. Moreover, the theoretical electronic and photovoltaic properties of all studied sensitizers have been compared with experimental results. All the 2-cyanoacrylamide derivative sensitizers demonstrated robust photovoltaic performance.

Investigation of the effect of a nitro group as an anchor group in dye-sensitized solar cells

“…They also measured the photovoltaic properties and overall photoconversion efficiencies of the DSSCs for sensitizers SFA5 and SFA6 (Figure 3), achieving the highest value available in the literature of 5.69% for a compound possessing an NO 2 anchor group. 10 Although the V oc values of the devices prepared with the F1 and F2 sensitizers are quite close to those prepared with the SFA5 and SFA6 sensitizers, the low PCE value is seen as being due to the effect of the groups directing the electron movement in the sensitizer structure.…”

“…In this study, a very high PCE value was reached compared to the literature using the NO 2 group as an anchor in compounds F1 and F2 used as sensitizers. Badawy et al 10 synthesized four innovative phenylacetonitrile and 2-cyanoacetamide derivatives of dyes, and studied how the presence of a thiophene spacer and different auxiliary acceptors affected the photophysical and electrochemical performance of the DSSC devices. They also measured the photovoltaic properties and overall photoconversion efficiencies of the DSSCs for sensitizers SFA5 and SFA6 (Figure 3), achieving the highest value available in the literature of 5.69% for a compound possessing an NO 2 anchor group.…”

Steric and Electronic Effect in Unsymmetrical Squaraine Dyes for Dye-Sensitized Solar Cells

“…Furthermore, the key photovoltaic parameters such as −Δ G inj and −Δ G reg were estimated as shown in eqs –, and their related data are summarized in Table . normalI normalP normalC normalE = normalL normalH normalE ( λ ) ϕ normali normaln normalj η normalr normale normalg η normalc normalc Δ G inj values for SQ-X dyes were calculated by (eq ) and they were found to be −0.66, −0.65, −0.60, −0.53, −0.48, and −0.42 V, respectively. This implies that driving force for the excited dye to inject electron into the conduction band of the TiO 2 would be feasible. , −Δ G inj is expressed as the energy difference between E ox* and E CB/TiO 2 as follow the eq − Δ G normali normaln normalg = E normalC normalB / normalT normali normalo 2 − E o x * …”

“…This implies that driving force for the excited dye to inject electron into the conduction band of the TiO 2 would be feasible. 50,51 −ΔG inj is expressed as the energy difference between E ox* and E CB/TiOd 2 as follow the eq 2…”

A Joint Theoretical and Experimental Study on a Tetrazole‐Anchored BODIPY‐Based Dye at the Surface of TiO2 for Dye‐Sensitized Solar Cell Applications

“…The modified donor and acceptor units provide control in features such as noncovalent binding sites, stability, electron-donating capacity, and aggregation. [27] In the literature, while triphenylamine, carbazole, phenothiazine, and coumarin derivatives are often preferred for the donor part, porphyrin, pyridine, and perylene derivatives are among the suitable candidates for the acceptor part. [28][29][30] The BODIPY dye compound with a tetrazole ring dye was created for the first time in the current work.…”