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Design and Implementation of Digital Phase Locked Loop for Single-Phase Grid-Tied PV Inverters
摘要： The rational design of porphyrin sensitizers is always crucial for dye-sensitized solar cells (DSSCs), since the change of only a single atom can have a significant influence on the photovoltaic performance. We incorporated the pyridothiadiazole group, as a stronger electron-withdrawing group, into the commonly well-established skeleton of D-porphyrin-triple bond-acceptor sensitizers by a single atom change for a well-known strong electron-withdrawing benzothiadiazole (BTD) unit as an auxiliary acceptor. The impact of the pyridothiadiazole group on the optical; electrochemical; and photovoltaic properties of D–π–A porphyrin sensitizers was investigated with comparison for a benzothiadiazole-substituted SGT-020 porphyrin. The pyridothiadiazole-substituted SGT-024 porphyrin dye was red-shifted so that the absorption range might be expected to achieve higher light harvest efficiency (LHE) than the SGT-020 porphyrin. However, all the devices were fabricated by utilizing SGT-020 and SGT-024, evaluated and found to achieve a cell efficiency of 10.3% for SGT-020-based DSSC but 4.2% for SGT-024-based DSSC under standard global AM 1.5G solar light conditions. The main reason is the lower charge collection efficiency of SGT-024-based DSSC than SGT-020-based DSSC, which can be attributed to the tilted dye adsorption mode on the TiO2 photoanode. This may allow for faster charge recombination, which eventually leads to lower Jsc, Voc and power conversion efficiency (PCE).
关键词： D–π–A structural porphyrin,charge collection efficiency,acceptor units,charge recombination,dye-sensitized solar cells
更新于2025-09-23 15:23:52
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Prediction of Second-Order Nonlinear Optical Properties of D–π–A Compounds Containing Novel Fluorene Derivatives: A Promising Route to Giant Hyperpolarizabilities
摘要： Herein, ?rst attempt has been made to utilize ?uorene-based dye-sensitized solar cell (DSSCs) dye JK-201 as potential nonlinear optical (NLO) material and for the theoretical designing of novel NLO chromophores JK-D1–JK-D12. DFT/TDDFT calculations were performed to compute the effect of p-linkers and acceptors-steered modulation on electronic, photophysical and NLO properties of JK-201 and JK-D1–JK-D12. Results illustrate that computed kmax (484.74 nm) and experimentally calculated kmax (481 nm) of JK-201 was found in good agreement. Maximum red shifted absorption spectrum was observed in JK-D12 with 599.38 nm. JK-D1–JK-D12 showed narrow energy gap and broader absorption spectrum as compared to JK-201. NBO analysis con?rmed the formation of charge separation state due to robust range of electrons/charge transfer from donor to acceptor via p-bridge. Giant NLO response was observed in all compounds. Particularly, JK-D12 displayed surprisingly large hai and btot computed 1376.74 (a.u.) and 405,731.84 (a.u.) respectively. Although literature is ?ooded with D–p–A compounds investigated for their DSSCs properties, but research reports on their NLO properties and utilization as NLO materials are completely deserted. Our research will open new horizons to explore DSSCs materials for NLO applications. This theoretical framework also exposed that ?uorene-substituted chromophores are excellent NLO candidates for modern hi-tech applications.
关键词： D–p–A organic chromophores,Acceptor units,Molecular modeling,Density functional theory,NLO response properties,p-Conjugated linkers
更新于2025-09-23 15:22:29
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First theoretical probe for efficient enhancement of nonlinear optical properties of quinacridone based compounds through various modifications
摘要： In this study, first attempt has been made for theoretical designing of quinacridone (QA) dye and new QA-based compounds (QA-1 to QA-9) were proposed by installing auxiliary donors (dimethylvinyl, methoxy, and N,N-dimethylamine), donor (diphenylamine) and acceptors (cyanoacrylic acid, CN and NO2) segments into fixed π-bridge QA. DFT and TDDFT calculations with B3LYP/6-31G(d,p) and CAM-B3LYP/6-31G(d,p) functional were used to shed light on the promising structure, charge transport and NLO properties. Introduction of auxiliary donors/donor and acceptor successfully modified the structure which led to superior NLO properties. An eye-catching NLO response was observed in all designed compounds. Interestingly, QA-9 exhibits appealingly large enhancement in NLO properties through ICT process with < α > and βtot computed to be 716.02 (a.u) and 128082.15 (a.u) respectively. UV–Vis results indicates the QA-9 most red shifted among all studied compounds with λmax = 489.02 nm. QA-1 to QA-9 showed narrow HOMO-LUMO energy gap as compared to QA which results in enhanced NLO response. NBO analysis confirms the formation of charge separation state in QA-1 to QA-9 due to successful migration of electrons from auxiliary donors/donor to acceptors via π-bridge. The present research evokes the scientific interest regarding the development of QA based tempting NLO compounds that can be beneficial in modern hi-tech applications.
关键词： Density functional theory,Molecular modeling,Quinacridone-based dyes,Donor and acceptor units,NLO properties,Two-state model
更新于2025-09-23 15:21:01
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Significant Influence of a Single Atom Change in Auxiliary Acceptor on Photovoltaic Properties of Porphyrin-Based Dye-Sensitized Solar Cells
摘要： The rational design of porphyrin sensitizers is always crucial for dye-sensitized solar cells (DSSCs), since the change of only a single atom can have a signi?cant in?uence on the photovoltaic performance. We incorporated the pyridothiadiazole group, as a stronger electron-withdrawing group, into the commonly well-established skeleton of D-porphyrin-triple bond-acceptor sensitizers by a single atom change for a well-known strong electron-withdrawing benzothiadiazole (BTD) unit as an auxiliary acceptor. The impact of the pyridothiadiazole group on the optical; electrochemical; and photovoltaic properties of D–π–A porphyrin sensitizers was investigated with comparison for a benzothiadiazole-substituted SGT-020 porphyrin. The pyridothiadiazole-substituted SGT-024 porphyrin dye was red-shifted so that the absorption range might be expected to achieve higher light harvest ef?ciency (LHE) than the SGT-020 porphyrin. However, all the devices were fabricated by utilizing SGT-020 and SGT-024, evaluated and found to achieve a cell ef?ciency of 10.3% for SGT-020-based DSSC but 4.2% for SGT-024-based DSSC under standard global AM 1.5G solar light conditions. The main reason is the lower charge collection ef?ciency of SGT-024-based DSSC than SGT-020-based DSSC, which can be attributed to the tilted dye adsorption mode on the TiO2 photoanode. This may allow for faster charge recombination, which eventually leads to lower Jsc, Voc and power conversion ef?ciency (PCE).
关键词： charge collection ef?ciency,dye-sensitized solar cells,D–π–A structural porphyrin,acceptor units,charge recombination
更新于2025-09-11 14:15:04
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Stable, carrier separation tailorable conjugated microporous polymers as a platform for highly efficient photocatalytic H2 evolution
摘要： The molecular design of highly photo-functional polymers with high charge separation efficiency and wide spectral absorption are long term quest for photocatalysis. Herein, we design and develop a series of nitrogen-containing conjugated microporous polymers (N-CMPs) with tailored donor-acceptor units for enhancing charge separation and light harvesting for visible light photocatalytic H2 production. By alternating the substitution position (o-, m-, or p-) and the number of electron donor (carbazole, diphenylamine) and acceptor (cyano) units on the 3D-core structure, a series of N-CMPs with adjustable donor-acceptor (D-A) charge separation efficiencies and tuneable band gaps in the range of 1.64-2.29 eV were obtained, enabling the precise control of the photocatalytic activity at the molecular level. The optimized N-CMP (4-CzPN) exhibits a higher visible light H2 production rate at 2103.2 μmol/h·g and the apparent quantum yield (AQY) at 420 nm reaches 6.4%. Furthermore, the 4-CzPN photocatalyst maintains excellent durability and recycling performance under 25 h continued light irradiation. The outstanding photocatalytic performance of the optimized N-CMPs with D-A structure is attributed to the enhanced polarity and conjugated degree of their core structure, which promotes charge separation and light absorption.
关键词： light absorption,donor-acceptor units,photocatalytic H2 production,conjugated microporous polymers,charge separation
更新于2025-09-04 15:30:14