Dataset Information

Effects of Alkoxy and Fluorine Atom Substitution of Donor Molecules on the Morphology and Photovoltaic Performance of All Small Molecule Organic Solar Cells.

ABSTRACT: Two benzothiadiazole (BT)-based small-molecule donors, SM-BT-2OR with alkoxy side chain and SM-BT-2F with fluorine atom substitution, were designed and synthesized for investigating the effect of the substituents on the photovoltaic performance of the donor molecules in all small molecule organic solar cells (SM-OSCs). Compared to SM-BT-2OR, the film of SM-BT-2F exhibited red-shifted absorption and deeper HOMO level of -5.36 eV. When blending with n-type organic semiconductor (n-OS) acceptor IDIC, the as-cast devices displayed similar PCE values of 2.33 and 2.76% for the SM-BT-2OR and SM-BT-2F-based devices, respectively. The SM-BT-2OR-based devices with thermal annealing (TA) at 120°C for 10 min showed optimized PCE of 7.20%, however, the SM-BT-2F-based device displayed lower PCE after the TA treatment, which should be ascribed to the undesirable morphology and molecular orientation. Our results reveal that for the SM-OSCs, the substituent groups of small molecule donors have great impact on the film morphology, as well as the photovoltaic performance.

SUBMITTER: Qiu B

PROVIDER: S-EPMC6146101 | biostudies-literature | 2018

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Effects of Alkoxy and Fluorine Atom Substitution of Donor Molecules on the Morphology and Photovoltaic Performance of All Small Molecule Organic Solar Cells.

Qiu Beibei B Chen Shanshan S Xue Lingwei L Sun Chenkai C Li Xiaojun X Zhang Zhi-Guo ZG Yang Changduk C Li Yongfang Y

Frontiers in chemistry 20180913

Two benzothiadiazole (BT)-based small-molecule donors, SM-BT-2OR with alkoxy side chain and SM-BT-2F with fluorine atom substitution, were designed and synthesized for investigating the effect of the substituents on the photovoltaic performance of the donor molecules in all small molecule organic solar cells (SM-OSCs). Compared to SM-BT-2OR, the film of SM-BT-2F exhibited red-shifted absorption and deeper HOMO level of -5.36 eV. When blending with <i>n</i>-type organic semiconductor (<i>n</i>-OS ...[more]

PMID: 30271770

Similar Datasets

Project description:To address the increasing demand of efficient photovoltaic compounds for modern hi-tech applications, efforts have been made herein to design and explore triazatruxene-based novel donor materials with greater efficiencies. Five new molecules, namely M1-M5, were designed by structural modification of acceptor moiety (rhodanine-3-acetic acid) of well known experimentally synthesized JY05 dye (reference R), and their optoelectronic properties are evaluated to be used as donor molecules in organic solar cells. In these molecules M1-M5, triazatruxene acts as a donor unit and benzene spaced different end-capped moieties including 2-(4-(dicyanomethylene)-2-thioxothiazolidin-3-yl)acetic acid (A1), (E)-2-(4-(1-cyano-2-methoxy-2-oxoethylidene)-2-thioxothiazolidin-3-yl)acetic acid (A2), (Z)-2-(3'-ethyl-4'-oxo-2,2'-dithioxo-3',4'-dihydro-2'H,5H-[4,5'-bithiazolylidene]-3(2H)-yl)acetic acid (A3), (Z)-2-(4'-(dicyano-methylene)-3'-ethyl-2,2'-dithioxo-3',4'-dihydro-2'H,5H-[4,5'-bithiazol-ylidene]-3(2H)-yl)acetic acid (A4) and 2-((4Z,4'E)-4'-(1-cyano-2-methoxy-2-oxoethylidene)-3'-ethyl-2,2'-dithioxo-3',4'-dihydro-2'H,5H-[4,5'-bithiazolylidene]-3(2H)-yl)acetic acid (A5) respectively, as acceptor units. The electronic, photophysical and photovoltaic properties of the designed molecules M1-M5 have been compared with reference molecule R. All designed molecules exhibit reduced energy gap in the region of 1.464-2.008 eV as compared to reference molecule (2.509 eV). Frontier molecular orbital (FMO) surfaces confirm the transfer of charge from donor to acceptor units. All designed molecules M1-M5 exhibited an absorption spectrum in the visible region and they were broader as compared to that of reference R. Especially, M5 with highest λ max value 649.26 nm and lowest transition energy value 1.90 eV was accredited to the strong electron withdrawing end-capped acceptor moiety A5. The highest value of open circuit voltage (V oc) 1.02 eV with respect to HOMOdonor-LUMOBTP-4Cl was shown by M5 among all investigated molecules which was 0.15 V larger than reference molecule R. The designed molecule M5 is proven to be the best candidate for both electron and hole transport mobilities due to its smallest λ e (0.0212 eV) and λ h (0.0062 eV) values among all studied molecules.

Project description:Small-molecule (SM)-based organic solar cells (OSCs) have dominated the photovoltaic industry on account of their efficient optical and electronic properties. This quantum mechanical study addresses a DFT study of pentacyclic aromatic bislactam (PCL)-based small molecules for extremely proficient OSCs. Five novel small molecules (PCLM1-PCLM5) retaining the A-π-A-π-D-π-A-π-A arrangement were fabricated from the reference PCLR. At the MPW1PW91/6-31G** level of theory, detailed profiling of these novel molecules was performed by accurately following DFT, along with the time-dependent density functional theory (TD-DFT) hypothetical simulations to analyze the UV-visible absorption (λmax), light-harvesting efficiency (LHE), dipole moment (μ), fill factor (FF), open-circuit voltage (V OC), power conversion efficiency (PCE), frontier molecular orbitals (FMOs), binding energy (E b), density of states (DOS), electrostatic potential (ESP), and transition density matrix (TDM) plots. Alteration of peripheral acceptors in all of the molecular structures drastically modified their charge-transfer properties, such as a strong light-harvesting capability in the range of 0.9993-0.9998, reduced exciton E b (from 0.34 to 0.39 eV), a reduced bandgap (E g) in the range of 1.66-1.99 eV, an elevated λmax (775-959 nm) along with a higher μ in the solvent phase (1.934-7.865 D) when studied in comparison with PCLR, possessing an LHE of 0.9986, an E b of 0.40, an E g 2.27 eV, λmax at 662 nm, and a μ of 0.628 D. The FMO analysis revealed the uniform dispersal of charge density entirely along the highest occupied (HOMO) and lowest unoccupied (LUMO) molecular orbitals in newly constructed moieties. Electron as well as hole mobility rates, V OC, FF, and PCE of all novel molecules (PCLM1-PCLM5) were higher as compared with those of PCLR, ultimately making them exceptional candidates for solar devices. Focusing on the outcomes, terminal acceptor modification was found to be a suitable method for the development of highly tuned OSCs in the future.

Dataset Information

Effects of Alkoxy and Fluorine Atom Substitution of Donor Molecules on the Morphology and Photovoltaic Performance of All Small Molecule Organic Solar Cells.

Publications

Effects of Alkoxy and Fluorine Atom Substitution of Donor Molecules on the Morphology and Photovoltaic Performance of All Small Molecule Organic Solar Cells.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets