Rational Design of Phenothiazine-Based Organic Dyes for Dye-Sensitized Solar Cells: The Influence of π-Spacers and Intermolecular Aggregation on Their Photovoltaic Performances

Abstract

Power conversion efficiency (PCE) is one of the important factors in influencing the overall performance of dye-sensitized solar cells (DSSCs), and precise prediction of PCE is a feasible strategy for preparing highly efficient DSSCs devices. In this work, we designed a series of phenothiazine-based organic dyes by introducing different π-spacers including the 4-isopropyl-4H-dithieno­[3,2-b:2′,3′-d]­pyrrole (DTP) and 2,7-dihydronaphtho­[1,2-d:5,6-d′]­diimidazole (NDI) to tune their photovoltaic properties. The present studies reveal that the PCE value of the DTP-based dye is estimated to be 8.55%, in excellent agreement with the experimentally available value (8.19%) observed in the reported analogue. In comparison to DTP, the strong electron-deficiency NDI group induces a remarkable red-shifting of maximum absorption band, broadening the optical absorption into the near-infrared region. As a consequence, the NDI-based dye achieves an impressive PCE value of 15.51%, which is expected to be a potential organic dye applied in DSSCs.

A two-step MM and QM/MM approach to model AIEE of aryloxy benzothiadiazole derivatives for optoelectronic applications

“…Of all derivatives, the nitro substituent has the lowest HOMO-LUMO gap with 2. conduction band of TiO 2 will facilitate easier electron injection to the conduction band. 56 For all the designed candidates, the HOMO levels (À6.41 to À5.72 eV) are lower than that for the I À /I 3 À redox couple (À4.80 eV). 57 Therefore, the regeneration of the oxidized dye is thermodynamically favorable.…”

3,10‐Diaryl Phenothiazines – One‐pot Synthesis and Conformational Tuning of Ground and Excited State Electronics

“…[12] In particular, conformationally restricted N-aryl phenothiazines with charge transfer character represent an interesting and promising class of compounds as efficient thermally activated delayed fluorescent (TADF) dyes in OLEDs. [13] Also, phenothiazines possess promising electroactive properties, mainly based on extraordinarily stable phenothiazinyl radical cations and low oxidation potentials they are applied in organic field effect transistors, [14] organic photovoltaics, [15] and in lithium batteries [16] as well as in photoredox catalysis. [17] Due to their non-planar "butterfly" shaped conformation, [18] N-substituted phenothiazines are used as a scaffold for the design of new aggregation-induced emission (AIE) and stimulation-sensitive emitting compounds.…”

Radical cations and dications of bis[1]benzothieno[1,4]thiazine isomers

“…[3][4][5][6][7][8] Electron-rich heterocycles, such as phenothiazine, are prominent structural motifs used in electroactive materials for batteries, [9][10][11] OLEDs, [12][13][14] and DSSCs. [15][16][17][18][19] They possess low oxidation potentials with fully chemically reversible oneelectron oxidations, low band gaps, and luminescent properties. [20][21][22] In addition to their convenient accessibility, their intrinsic properties are easily fine tunable by synthetic functionalization.…”