Molecular Design and Application of a Photovoltaic Polymer with Improved Optical Properties and Molecular Energy Levels

2015 ◽  
Vol 48 (11) ◽  
pp. 3493-3499 ◽  
Author(s):  
Huifeng Yao ◽  
Hao Zhang ◽  
Long Ye ◽  
Wenchao Zhao ◽  
Shaoqing Zhang ◽  
...  
Keyword(s):  
Optical Properties ◽  
Molecular Design ◽  
Energy Levels ◽  
Design And Application

scholarly journals Multi-fidelity prediction of molecular optical peaks with deep learning

2021 ◽  
Author(s):  
Kevin Greenman ◽  
William Green ◽  
Rafael Gómez-Bombarelli
Keyword(s):  
Optical Properties ◽  
Statistical Methods ◽  
Message Passing ◽  
Density Functional ◽  
Molecular Design ◽  
Chemical Space ◽  
Epistemic Uncertainty ◽  
Computational Cost ◽  
Regression Tree ◽  
Td Dft

Optical properties are central to molecular design for many applications, including solar cells and biomedical imaging. A variety of ab initio and statistical methods have been developed for their prediction, each with a trade-off between accuracy, generality, and cost. Existing theoretical methods such as time-dependent density functional theory (TD-DFT) are generalizable across chemical space because of their robust physics-based foundations but still exhibit random and systematic errors with respect to experiment despite their high computational cost. Statistical methods can achieve high accuracy at a lower cost, but data sparsity and unoptimized molecule and solvent representations often limit their ability to generalize. Here, we utilize directed message passing neural networks (D-MPNNs) to represent both dye molecules and solvents for predictions of molecular absorption peaks in solution. Additionally, we demonstrate a multi-fidelity approach based on an auxiliary model trained on over 28,000 TD-DFT calculations that further improves accuracy and generalizability, as shown through rigorous splitting strategies. Combining several openly-available experimental datasets, we benchmark these methods against a state-of-the-art regression tree algorithm and compare the D-MPNN solvent representation to several alternatives. Finally, we explore the interpretability of the learned representations using dimensionality reduction and evaluate the use of ensemble variance as an estimator of the epistemic uncertainty in our predictions of molecular peak absorption in solution. The prediction methods proposed herein can be integrated with active learning, generative modeling, and experimental workflows to enable the more rapid design of molecules with targeted optical properties.

Azobenzene dyads containing fullerene, porphyrin and pyrene chromophores: Molecular design and optical properties

2022 ◽  
Vol 197 ◽  
pp. 109858
Author(s):  
Pasquale Porcu ◽  
Aldo S. Estrada-Montaño ◽  
Mireille Vonlanthen ◽  
Fabián Cuétara-Guadarrama ◽  
Israel González-Méndez ◽  
...  
Keyword(s):  
Optical Properties ◽  
Molecular Design

scholarly journals Polymerized small molecular acceptor based all-polymer solar cells with an efficiency of 16.16% via tuning polymer blend morphology by molecular design

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jiaqi Du ◽  
Ke Hu ◽  
Jinyuan Zhang ◽  
Lei Meng ◽  
Jiling Yue ◽  
...  
Keyword(s):  
Solar Cells ◽  
Molecular Design ◽  
Polymer Solar Cells ◽  
Energy Levels ◽  
Photovoltaic Performance ◽  
Electronic Energy ◽  
Force Microscopy ◽  
Transmission Electron ◽  
Electronic Energy Levels ◽  
20 Nm

AbstractAll-polymer solar cells (all-PSCs) based on polymerized small molecular acceptors (PSMAs) have made significant progress recently. Here, we synthesize two A-DA’D-A small molecule acceptor based PSMAs of PS-Se with benzo[c][1,2,5]thiadiazole A’-core and PN-Se with benzotriazole A’-core, for the studies of the effect of molecular structure on the photovoltaic performance of the PSMAs. The two PSMAs possess broad absorption with PN-Se showing more red-shifted absorption than PS-Se and suitable electronic energy levels for the application as polymer acceptors in the all-PSCs with PBDB-T as polymer donor. Cryogenic transmission electron microscopy visualizes the aggregation behavior of the PBDB-T donor and the PSMA in their solutions. In addition, a bicontinuous-interpenetrating network in the PBDB-T:PN-Se blend film with aggregation size of 10~20 nm is clearly observed by the photoinduced force microscopy. The desirable morphology of the PBDB-T:PN-Se active layer leads its all-PSC showing higher power conversion efficiency of 16.16%.

Analysis of electronic structure and optical properties of N-doped SiO2 based on DFT calculations

2015 ◽  
Vol 29 (19) ◽  
pp. 1550100 ◽  
Author(s):  
Sui-Shuan Zhang ◽  
Zong-Yan Zhao ◽  
Pei-Zhi Yang
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
Band Gap ◽  
Impurity Concentration ◽  
Nitrogen Concentration ◽  
Energy Levels ◽  
Optical Parameter ◽  
Doping Effects ◽  
N Doping ◽  
The Relationship

The crystal structure, electronic structure and optical properties of N-doped [Formula: see text] with different N impurity concentrations were calculated by density function theory within GGA[Formula: see text]+[Formula: see text]U method. The crystal distortion, impurity formation energy, band gap, band width and optical parameter of N-doped [Formula: see text] are closely related with N impurity concentration. Based on the calculated results, there are three new impurity energy levels emerging in the band gap of N-doped [Formula: see text], which determine the electronic structure and optical properties. The variations of optical properties induced by N doping are predominately determined by the unsaturated impurity states, which are more obvious at higher N impurity concentration. In addition, all the doping effects of N in both [Formula: see text]-quartz [Formula: see text] and [Formula: see text]-quartz [Formula: see text] are very similar. According to these findings, one could understand the relationship between nitrogen concentration and optical parameter of [Formula: see text] materials, and design new optoelectrionic Si–O–N compounds.

Linear and Non-Linear Optical Properties of (2-Cyano-5-Methoxy-1,4-Phenylenevinylene) and Paraphenylenevinylene Copolymers

1992 ◽  
Vol 277 ◽  
Author(s):  
Jang-Joo Kim ◽  
Do-Hoon Hwang ◽  
Shin-Woong Kang ◽  
Hong-Ku Shim
Keyword(s):  
Optical Properties ◽  
Molecular Design ◽  
Water Soluble ◽  
New Approach ◽  
Electro Optic ◽  
Precursor Polymers ◽  
Non Linear ◽  
Linear Optical Properties ◽  
Precursor Route ◽  
Linear Optical

ABSTRACTPoly(CMPV-co-PV) have been synthesized via water soluble sulfonium salt precursor route and their linear and non-linear optical properties were characterized. The electro-optic response was stable up to 100°C when the materials were poled during the elimination. The thermal stability and mechanical strength of PPV and its derivatives, and easy processibility from the precursor polymers suggest a new approach for the molecular design of the 2nd order non-linear optical polymers.

Energy Band Models for Spatially Dispersive Dielectric Media

1975 ◽  
Vol 53 (19) ◽  
pp. 2095-2122 ◽  
Author(s):  
J. E. Sipe ◽  
J. Van Kranendonk
Keyword(s):  
Optical Properties ◽  
Degrees Of Freedom ◽  
Energy Levels ◽  
Equations Of Motion ◽  
Dispersive Media ◽  
Energy Bands ◽  
Macroscopic Theory ◽  
Mechanical Coupling ◽  
Radiation Theory ◽  
Spatially Dispersive

The effects of spatial dispersion on the optical properties of dielectric crystals, arising from the broadening of the molecular energy levels into energy bands by the intermolecular interaction, are discussed both in the microscopic and the macroscopic theory. The microscopic equations of motion for the internal degrees of freedom describing the molecular excitations are derived using semiclassical radiation theory, and the conditions are given under which a description in terms of only the dipole moment is possible. The corresponding macroscopic equations are derived and the nature of the boundary conditions and integral relations appearing in the theory are discussed. The characterization of spatially dispersive media as nonlocal is shown to be based on a misinterpretation of the meaning of the integral kernels relating to infinite media. The breakdown of the macroscopic theory due to the previously predicted onset of an antiresonant response is explicitly demonstrated for slab geometries for which rigorous solutions are given of both the macroscopic and the microscopic equations. Finally, we introduce a mechanical coupling varying exponentially with the intermolecular separation, which provides a two parameter model for the exciton bands and which prevents the proliferation of microscopic refractive indices occurring in other models. The exp model is shown to be useful to study the dependence of the optical properties for example on the effective mass and the width of an exciton band.

Ab initio study of oxygen vacancy effects on electronic and optical properties of NiO

MRS Advances ◽  
2016 ◽  
Vol 1 (37) ◽  
pp. 2617-2622 ◽  
Author(s):  
John Petersen ◽  
Fidele Twagirayezu ◽  
Pablo D. Borges ◽  
Luisa Scolfaro ◽  
Wilhelmus Geerts
Keyword(s):  
Optical Properties ◽  
Density Functional ◽  
Local Density ◽  
Optical Transition ◽  
Energy Levels ◽  
Density Functional Theory Calculations ◽  
Local Density Of States ◽  
Functional Theory ◽  
Electronic And Optical Properties ◽  
O Vacancy

ABSTRACTDensity Functional Theory calculations of electronic and optical properties of NiO, with and without O vacancies, are the focus of this work. Two bands, one fully occupied and the other unoccupied, induced by an O vacancy, are found in the gap. These energy levels are identified and analyzed by means of a local density of states (LDOS) calculation, and notable crystal field splitting can be seen. The real and imaginary parts of the dielectric function are calculated, and an additional optical transition can be seen at lower energy, which can be attributed to the O vacancy induced state in the band gap.

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