Computationally Assisted Multistage Design and Prediction Driving the Discovery of Deep-Ultraviolet Nonlinear Optical Materials

Author(s):  
Zhihua Yang ◽  
Shilie Pan

With the rapid development of computer technology, material design and crystal-structural prediction based on density functional theory have become one "top-down" strategy to accelerate the process of advanced materials discovery....

2020 ◽  
Vol 2 (2) ◽  
pp. 062-062

Flexible electronics have attracted great attention due to their salient features and significant roles in the fields of energy, information, sensing, displays, smart skins, wearable systems, biomedical diagnostics, and artificial intelligence, etc. The past years have witnessed the rapid development of advanced materials and devices for flexible electronics. This special issue aims to collect high quality articles focused on thin-film materials, devices and carrier dynamics in flexible electronics and optoelectronics. It is desirable to search a variety of functional films including metallic, organic, inorganic, hybrid and composite materials for developing different types of flexible transistors, sensors, actuators, photodetectors, photovoltaic devices, light-emitting devices and beyond. It may contain, but not limited to material design, thin-film processing, structure regulation, property optimization, structure-property relationship, device engineering, and potential applications. Meanwhile, fundamental investigations on surface and interface characteristics, energy level alignments, charge and energy transfer processes, device operation mechanisms, and carrier dynamics related with advanced techniques such as ultrafast transient absorption and time-resolved (TR) spectroscopy, are welcome for understanding the thin-film materials and flexible devices. I kindly invite you to submit a manuscript(s) for this Special Issue. Full papers, communications, and reviews are all welcome.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Chunmei Huang ◽  
Miriding Mutailipu ◽  
Fangfang Zhang ◽  
Kent J. Griffith ◽  
Cong Hu ◽  
...  

AbstractMore than 3900 crystalline borates, including borate minerals and synthetic inorganic borates, in addition to a wealth of industrially-important boron-containing glasses, have been discovered and characterized. Of these compounds, 99.9 % contain only the traditional triangular BO3 and tetrahedral BO4 units, which polymerize into superstructural motifs. Herein, a mixed metal K5Ba2(B10O17)2(BO2) with linear BO2 structural units was obtained, pushing the boundaries of structural diversity and providing a direct strategy toward the maximum thresholds of birefringence for optical materials design. 11B solid-state nuclear magnetic resonance (NMR) is a ubiquitous tool in the study of glasses and optical materials; here, density functional theory-based NMR crystallography guided the direct characterization of BO2 structural units. The full anisotropic shift and quadrupolar tensors of linear BO2 were extracted from K5Ba2(B10O17)2(BO2) containing BO2, BO3, and BO4 and serve as guides to the identification of this powerful moiety in future and, potentially, previously-characterized borate minerals, ceramics, and glasses.


2020 ◽  
Vol 62 (1) ◽  
pp. 120-129
Author(s):  
S. Moufok ◽  
B. Amrani

AbstractThe search for a new material with unparalleled properties has attracted the interest of the scientific community due to rapid development of technology and it can be very inspiring to the future experiments. In this paper, electronic structure and optical properties of the new rare earth coinage-metal chalconegides YCuChO (Ch=S, Se, Te) are investigated in detail using state-of-the art density functional theory (DFT). Both the GGA-PBEsol and TB-mBJ functionals were used to describe the exchange-correlation interactions. These compounds are novel and have not been synthesized before. The optimized structural parameters, viz., lattice parameters and atomic position coordinates, are predicted. The analyses of the electronic properties indicate that the studied compounds are wide direct bandgap semiconductors. The calculated bandgaps varying from 1.69 eV (for the Te compound) to 2.5 eV (for the S compound) with the mBJ approach. Moreover, the optical properties of these compounds were comprehensively studied and discussed in terms of the dielectric function and loss function. The results provide theoretical support for the exploration of YCuChO (Ch=S, Se, Te) materials in potential optoelectronic applications.


Author(s):  
Natalia Pino ◽  
Jennifer Quinchia ◽  
Santiago Gómez ◽  
Juan F. Espinal ◽  
Alejandro Montoya ◽  
...  

The hydrodeoxygenation (HDO) of acetophenone was evaluated in liquid phase and gas phase over monometallic Pt/SiO 2 , Co/SiO 2 and bimetallic Pt–Co/SiO 2 catalysts. The influence of reaction time and loading of the catalyst were analysed by following the conversion and products selectivity. Phenylethanol, cyclohexylethanone and cyclohexylethanol are the main products of reaction using the Pt/SiO 2 catalyst. By contrast, ethylbenzene and phenylethanol are the only products formed on the Co/SiO 2 and Pt–Co/SiO 2 catalysts. The bimetallic catalyst is more stable as a function of time and more active towards the HDO process than the monometallic systems. The presence of an organic solvent showed only minor changes in product yields with no effect on the product speciation. Periodic density functional theory analysis indicates a stronger interaction between the carbonyl group of acetophenone with Co than with Pt sites of the mono and bimetallic systems, indicating a key activity of oxophilic sites towards improved selectivity to deoxygenated products. This article is part of the theme issue ‘Bio-derived and bioinspired sustainable advanced materials for emerging technologies (part 2)’.


2013 ◽  
Vol 303-306 ◽  
pp. 2563-2566
Author(s):  
Xin Wei Zhang ◽  
Cun Li ◽  
Jun Qi Xu

A series of chiral [6]helicenes have been designed using the molecular engineering of organic nonlinear optical materials. The geometries of [6]helicenes 1, 2, 3, 4,5 are optimized using density functional theory (DFT-B3LYP) method at the 6-31g (d, p) basis set level. Based on the obtained stable molecular configuration, we adopt the TDHT/PM3 method and time-dependent density-functional theory (TD-DFT) to calculate the nonlinear optical (NLO) properties and electronic spectra of these molecules. Results show that the static hyperpolarizability βµ alternates between positive value and negative value, whereas it remains positive for the molecues 2 and 3 which have medium magnitudes βµ, 3.4×10-30esu and 9.6×10-30esu respectively. In molecule 5, there exists two competitive charge transfers that reduce the hyperpolarizability β.


Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 284
Author(s):  
Zheng Tang ◽  
Chaofan Chang ◽  
Feng Bao ◽  
Lei Tian ◽  
Huichao Liu ◽  
...  

The rapid development of electronic devices with high integration levels, a light weight, and a multifunctional performance has fostered the design of novel polymer materials with low dielectric constants, which is crucial for the electronic packaging and encapsulation of these electronic components. Theoretical studies are more efficient and cost-effective for screening potential polymer materials with low dielectric constants than experimental investigations. In this study, we used a molecular density functional theory (DFT) approach combined with the B3LYP functional at the 6-31+G(d, p) basis set to validate the feasibility of predicting static dielectric constants of the polymer materials. First, we assessed the influence of the basis sets on the polarizability. Furthermore, the changes of polarizability, polarizability per monomer unit, and differences in polarizability between the consecutive polymer chains as a function of the number of monomers were summarized and discussed. We outlined a similar behavior for the volume of the polymers as well. Finally, we simulated dielectric constants of three typical polymer materials, polyethylene (PE), polytetrafluoroethylene (PTFE), and polystyrene (PS), by combining with the Clausius–Mossotti equation. The simulated results showed excellent agreement with experimental data from the literature, suggesting that this theoretical DFT method has great potential for the molecular design and development of novel polymer materials with low dielectric constants.


Molecules ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 193
Author(s):  
Xinli Wang ◽  
Xiang Lin ◽  
Renfu Li ◽  
Zexin Wang ◽  
Wei Liu ◽  
...  

In this work, we synthesized a pair of positional isomers by attaching a small electron-donating pyrrolidinyl group at ortho- and para-positions of a conjugated core. These isomers exhibited totally different fluorescent properties. PDB2 exhibited obvious aggregation-induced emission properties. In contrast, PDB4 showed the traditional aggregation-caused quenching effect. Their different fluorescent properties were investigated by absorption spectroscopy, fluorescence spectroscopy, density functional theory calculations and single-crystal structural analysis. These results indicated that the substituent position of the pyrrolidinyl groups affects the twisted degree of the isomers, which further induces different molecular packing modes, thus resulting in different fluorescent properties of these two isomers. This molecular design concept provided a new accurate strategy for designing new aggregation-induced emission luminogens.


2020 ◽  
Vol 11 ◽  
pp. 1577-1589
Author(s):  
Jari Järvi ◽  
Patrick Rinke ◽  
Milica Todorović

Identifying the atomic structure of organic–inorganic interfaces is challenging with current research tools. Interpreting the structure of complex molecular adsorbates from microscopy images can be difficult, and using atomistic simulations to find the most stable structures is limited to partial exploration of the potential energy surface due to the high-dimensional phase space. In this study, we present the recently developed Bayesian Optimization Structure Search (BOSS) method as an efficient solution for identifying the structure of non-planar adsorbates. We apply BOSS with density-functional theory simulations to detect the stable adsorbate structures of (1S)-camphor on the Cu(111) surface. We identify the optimal structure among eight unique types of stable adsorbates, in which camphor chemisorbs via oxygen (global minimum) or physisorbs via hydrocarbons to the Cu(111) surface. This study demonstrates that new cross-disciplinary tools, such as BOSS, facilitate the description of complex surface structures and their properties, and ultimately allow us to tune the functionality of advanced materials.


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