Superiority of D–A–D over D–A type of organic dyes for the application in dye-sensitized solar cell

Origin of Different Photovoltaic Activities in Regioisomeric Small Organic Molecule Solar Cells: The Intrinsic Role of Charge Transfer Processes

“…It is known that the hybrid functional B3LYP fits well for representing the optimized ground state geometries for the individual and composite systems. 7,17,30 However, as could be found in Table 1, HSE03/HSE06 reproduces the electronic energy gap quite accurately, while PBE1PBE estimates the HOMO energy of the individual molecules with reasonable good accuracy which is a very important parameter for determining the charge transfer rate. 17,30,31 We performed time-dependent DFT (TDDFT) calculations to have the electronic excitation energy along with the absorption spectra of the molecules.…”

“…were used to calibrate the geometric parameters and electronic properties with the experimentally determined values. It is known that the hybrid functional B3LYP fits well for representing the optimized ground state geometries for the individual and composite systems. ,, However, as could be found in Table , HSE03/HSE06 reproduces the electronic energy gap quite accurately, while PBE1PBE estimates the HOMO energy of the individual molecules with reasonable good accuracy which is a very important parameter for determining the charge transfer rate. ,, We performed time-dependent DFT (TDDFT) calculations to have the electronic excitation energy along with the absorption spectra of the molecules. The same table (Table ) indicates that the long-range corrected density functional, CAM-B3LYP compares the computed absorption maxima (λ max ) of the molecules very nicely with that of the experimentally determined values for regioisomeric FBT molecules .…”

“…π-Conjugated small organic molecules have recently drawn serious attention in fabricating cost-effective photovoltaic devices. − There are two major advantages which attract them in solar cell industry. First, their structural flexibility is helpful for optimizing random blend morphology in bulk heterojunction (BHJ) technique , and second, the electronic and optical band gap of the molecules could easily be tuned through chemical functionalization. ,− In the last couple of years, a significant effort has been devoted for the rational design and synthesis of conjugated small organic molecules and their successful implementation in photovoltaic devices. ,− In most of the cases, fullerenes and their derivatives are the common acceptors. , However, performance of the photovoltaic cells composed of organic molecules is very much dependent upon the donor architecture comprising different types of electron-rich and electron-deficient counterparts which modulate intra/intermolecular charge transfer and recombination dynamics. − …”

Novel D-A-D Fluorescent Dyes Based on 9-(p-Tolyl)-2,3,4,4a,9,9a-hexahydro-1H-carbazole as a Donor Unit for Solution-Processed Organic Light-Emitting-Diodes

“…Among the most significant applications of compounds from this class is the possibility of their use as an emitting material for Li-Fi technologies [ 9 ]. Particular attention is paid to structures of the D-A-D type, since the introduction of an additional donor improves the properties of the intramolecular charge transfer (ICT) mechanism [ 10 , 11 ]. Interest in dyes from this class is primarily associated with the ability to vary donor and acceptor molecular fragments.…”

Tuning the BODIPY core for its potential use in DSSC: a quantum chemical approach

“…Despite of this high efficiencies, potential application of Ruthenium complexes in DSSCs is restricted owing to their relatively cost effectiveness and most importantly they are environmentally hazardous. During the past two decades, various attempts were made with different metal-free organic dyes with architectures donor-(π-spacer)-acceptor (D-π-A) [4][5][6], D-A-D [7][8][9][10], etc. in the hope to find and replacement for metal complex dyes.…”