DSSC holds well in its metal usage reduction efforts compared to the available market panels and is generally a little less highlighted for habitat destruction risks. One of the types of thin-film and nano structure-based solar cells is dye-sensitized solar cells (DSSC), which utilize organic and inorganic materials as components. Still, due to environmental harm, metallic complexes pose a significant threat and have an exhaustion limit. State-of-the-art research in solar technologies has led to the development of thin sensitizing films, almost to the nanoscale. Accordingly, we can assume that this theoretical investigation is predictable to provide guidance for experimental synthesis of greatly efficient metal-free organic dyes based on carbazole for DSSC applications. In addition, the effects of the dyes adsorption on TiO2 surface, absorption spectra and energy levels were evaluated. The results of theoretical calculations of these dyes showed that the variation of π-spacer group could increase the open-circuit photovoltage, enhance light absorption ability and intramolecular charge transfer properties, reduce energy gap, thus leading to improved photovoltaic performance. Density functional theory (DFT) and time-dependent DFT (TD-DFT) methods have been used to investigate the geometrical structures, absorption properties, molecular electrostatic potential, and some important parameters in relation with the short-circuit current density (JSC) and the open-circuit photovoltage (VOC), such as nonlinear optical properties (NLO), light-harvesting efficiency (LHE), electron injection driving force (ΔGinject), total reorganization energy (λtotal), and chemical reactivity.
HOMO LUMO ORGANIC CHEMISTRY SERIES
We believe this approach can be integrated into genetic algorithms by biasing morphing operations in favour of those which are likely to be successful, leading to faster molecular discovery and greener chemistry.Ī series of D-A-π-A metal-free organic dyes (Di, i = 1–8) have been taken into account to study the influence of different π-spacer groups on their efficiency in dye-sensitized solar cells (DSSCs). We go on to provide proof-of-concept illustrations of this approach to optimizing the visible absorption of acenes and the emission of radical OLEDs. We then show how by combining electronic structure theory and intensity borrowing perturbation theory we can predict whether or not the proposed morphing operations will achieve the desired spectral alteration, and thereby derive widely-applicable design rules. We firstly adapt the Thomas-Reiche-Kuhn sum rule to organic chromophores and show how this indicates how easily the absorption and emission of a molecule can be improved. In this perspective we address both of these challenges from first principles. However, these approaches rely on a molecular database or many electronic structure calculations, and significant computational savings could be achieved if there was prior knowledge of (i) whether the optoelectronic properties of a parent molecule could easily be improved and (ii) what morphing operations on a parent molecule could improve these properties. This raises the question: how can we predict a potential chemical structure from these properties? Approaches that attempt to tackle this inverse design problem include virtual screening, active machine learning and genetic algorithms. Journal of Computational Chemistry published by Wiley Periodicals, Inc.The discovery of molecules with tailored optoelectronic properties such as specific frequency and intensity of absorption or emission is a major challenge in creating next-generation organic light-emitting diodes (OLEDs) and photovoltaics. NIR absorption charge-transfer excitations density functional calculations design rules donor-acceptor systems. Journal of Computational Chemistry published by Wiley Periodicals, Inc. Design principles could be developed from these analyses, which led to a proof-of-concept linear D-π-A with a strong excited-state intramolecular charge transfer and a NIR absorption at 879 nm. The trends in HOMO-LUMO gaps of the model dyes correlate with the excitation energies computed with time-dependent density functional theory at CAMY-B3LYP. Quantitative Kohn-Sham molecular orbital analysis enables accurate fine-tuning of the electronic properties of the π-conjugated aromatic cores by effecting their size, including silaaromatics, adding donor and acceptor substituents, and manipulating the D-π-A torsional angle. Principles are presented for the design of functional near-infrared (NIR) organic dye molecules composed of simple donor (D), spacer (π), and acceptor (A) building blocks in a D-π-A fashion.
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