Rational Design of Low-Band Gap Star-Shaped Molecules With 2,4,6-Triphenyl-1,3,5-triazine as Core and Diketopyrrolopyrrole Derivatives as Arms for Organic Solar Cells Applications

Abstract

A series of D–A novel star-shaped molecules with 2,4,6-triphenyl-1,3,5-triazine (TPTA) as core, diketopyrrolo[3,4-c]pyrrole (DPP) derivatives as arms, and triphenylamine (TPA) derivatives as end groups have been systematically investigated for organic solar cells (OSCs) applications. The electronic, optical, and charge transport properties were studied using density functional theory (DFT) and time-dependent DFT (TD-DFT) approaches. The parameters such as energetic driving force ΔEL−L, adiabatic ionization potential AIP, and adiabatic electron affinity AEA were also calculated at the same level. The calculated results show that the introduction of different groups to the side of DPP backbones in the star-shaped molecules can tune the frontier molecular orbitals (FMOs) energy of the designed molecules. The designed molecules can provide match well with those of typical acceptors PCBM ([6,6]-phenyl-C61-butyric acid methyl ester) and PC71BM ([6,6]-phenyl-C71-butyric acid methyl ester). Additionally, the absorption wavelengths of the designed molecules show bathochromic shifts compared with that of the original molecule, respectively. The introduction of different groups can extend the absorption spectrum toward longer wavelengths, which is beneficial to harvest more sunlight. The calculated reorganization energies suggest that the designed molecules are expected to be the promising candidates for ambipolar charge transport materials except molecule with benzo[c]isothiazole group can be used as hole and electron transport material. Moreover, the different substituent groups do not significantly affect the stability of the designed molecules.

In search of Covalent Organic Frameworkphotocatalysts: A DFT-based screening approach

“…This observation agrees with the photophysical nature of these organic groups known for having visible-light absorbing properties. 13,23,[33][34][35][36][37][38] The presence of these groups has been reported for applications involving visible light absorption in COFs. in this plot are desired to achieve the minimum requirement of 10% solar-to-hydrogen (STH) efficiency for profitable industrialization.…”

Cascade Radical Pathway-Enabled Nitrogen–Sulfur Coupling: Access to Isothiazolo[3,4-b]-meso-tetraarylporphyrins

“…Moreover, these macrocycles are suitable constituents for constructing the dye-sensitized solar cells and supramolecular frameworks due to their exceptional characteristics such as rigid and flat molecular structure, high thermal stability, strong absorption and emission of light, and a narrow energy gap between their highest occupied molecular orbital and lowest unoccupied molecular orbital. , Hence, a wide range of synthetic strategies were devised to construct diverse β- and meso -functionalized porphyrinic systems through peripheral modifications in previous years. − Additionally, porphyrins fused with imidazole and triazole ring systems have shown their importance as fundamental building blocks for multiporphyrinic arrays and oligomers that exhibited enhanced electronic properties. , On the other hand, isothiazole, another class of five-membered heterocycles present as a pharmacophore in many biologically active compounds, displayed a wide range of pharmaceutical profiles such as anticancer, antidiabetic, anti-Alzheimer, anticonvulsive, and antithrombotic activity . Furthermore, isothiazole-embedded molecules have also shown lower band gaps and thereby found to be beneficial for organic solar cell applications . Considering the biological and material attributes of porphyrin and isothiazole scaffolds, we envisaged constructing an isothiazole ring system on the periphery of meso -tetraarylporphyrins for the study of their photophysical characteristics.…”

“…29 Furthermore, isothiazole-embedded molecules have also shown lower band gaps and thereby found to be beneficial for organic solar cell applications. 30 Considering the biological and material attributes of porphyrin and isothiazole scaffolds, we envisaged constructing an isothiazole ring system on the periphery of meso-tetraarylporphyrins for the study of their photophysical characteristics. According to the literature reports, simple 2,1-benzisothiazoles were synthesized by employing 2-nitrobenzyl mercaptan derivatives, 31−33 2-aminobenzyl mercaptan, 34 o-toluidines, 35,36 sulfur diimide derivatives, 37 o-aminothiobenzamides, 38 o-nitrothiobenzamides, 38 oazidoarylthioketones, 39 and 2-aminobenzothiohydrazides 40 as starting substrates under diverse reaction conditions (Scheme 1).…”

Introducing Porphyrin Units by Random Copolymerization Into NDI-Based Acceptor for All Polymer Solar Cells

“…Generally, the high-quality n-type polymer materials are primarily based on the functionalized arenes of imides, e.g., diketopyrrolopyrrole (DPP) (Li et al, 2014(Li et al, , 2015Zhang and Jin, 2019), naphthalene diimide (NDI) (Bhosale et al, 2008), perylene diimide (PDI) (Seo et al, 2011), bithiophene imide (BTI) (Wang et al, 2017), and double B←N (boron-nitrogen coordination bond) bridged bipyridine (BNBP) (Dou et al, 2016). In these various n-type organic semiconductors materials, NDI-based copolymers, especially poly(2,7-bis(2-octyldodecyl)benzo [lmn][3,8]phenanthroline-1,3,6,8(2H,7H)-tetraone-4,9-diyl)([2,2 ′ ]bithiophenyl-5,5 ′ -diyl) (N2200), are the most outstanding one as all-PSC acceptor because of its good solubility and high electron mobility (Yan et al, 2009;Gao et al, 2016).…”