First-principles study on the lattice plane and termination dependence of the electronic properties of the NiO/CH3NH3PbI3 interfaces

2018 ◽  
Vol 6 (30) ◽  
pp. 8226-8233 ◽  
Author(s):  
Longhua Li ◽  
Jianli Mi ◽  
Yangchun Yong ◽  
Baodong Mao ◽  
Weidong Shi

Density functional theory (DFT) and non-equilibrium Green's function (NEGF) calculations give an insight at an atomistic level into the structure–property relationship of the nickel oxide/organometal halide perovskite (NiO/MAPbI3) interface.

2018 ◽  
Vol 20 (40) ◽  
pp. 25822-25828 ◽  
Author(s):  
Jonathan J. Heath ◽  
Marcelo A. Kuroda

We characterize the structure–property relationship of alkali metal elements in oxygen-passivated graphene pores using the density functional theory. We identify common trends in these systems based on their structural and electronic properties.


2016 ◽  
Vol 94 (9) ◽  
pp. 794-801
Author(s):  
Kai-Li Zhu ◽  
Le-yan Liu ◽  
Zhi-Yuan Geng

Two series of dyes have been designed and theoretically characterized through density functional theory and time-dependent density functional theory to systematically explore the structure–property relationship of dyes with D–A–π–A architecture and the performance of dye-sensitized solar cells, particularly the influence of the π-bridge, including its alkyl side chain, adding additional conjugate spacer, displacement, and separation of π-bridge. Key parameters associated with the short-circuit current density Jsc and open-circuit photovoltage Voc were characterized and analyzed in detail. All of the analysis results manifest that dye H1 should be the best candidate to fabricate dye-sensitized solar cells owing to the best optical absorption property (a broad absorption band from 300 to 900 nm for adsorbed dye) and other outstanding parameters.


2011 ◽  
Vol 311-313 ◽  
pp. 526-529
Author(s):  
Cai Juan Xia ◽  
Han Chen Liu ◽  
Ji Xin Yin

Using non-equilibrium Green’s function formalism combined with first-principles density functional theory, we investigate the electronic transport properties of a triangle terarylene(open- and closed-ring forms) optical molecular switch. The influence of the HOMO-LUMO gaps and the spatial distributions of molecular orbitals on the quantum transport through the molecular device is discussed. Theoretical results show that the conductance of the closed-ring is 3-8 times larger than that of open-ring, which expect that this system can be one of good candidates for optical switches due to this unique advantage, and may have some potential applications in future molecular circuit.


2015 ◽  
Vol 80 (8) ◽  
pp. 1035-1049 ◽  
Author(s):  
Katarina Nikolic ◽  
Mara Aleksic ◽  
Vera Kapetanovic ◽  
Danica Agbaba

Study of the adsorption and electroreduction behavior of cefpodoxime proxetil, cefotaxime, desacetylcefotaxime, cefetamet, ceftriaxone, ceftazidime, and cefuroxime axetile at the mercury electrode surface has been performed using Cyclic (CV), Differential Pulse (DPV), and Adsorptive Stripping Differential Pulse Voltammetry (AdSDPV). The Quantitative Structure Property Relationship (QSPR) study of the seven cephalosporins adsorption at the mercury electrode has been based on the density functional theory DFT-B3LYP/6-31G (d,p) calculations of molecular orbitals, partial charges and electron densities of analytes. The DFT-parameters and QSPR model explain well the process of adsorption of the examined cephalosporins. QSPR study defined that cefalosporins with lower charge of sulphur in the thiazine moiety, lower electron density on the nitrogen atom of the N-O bond, higher number of hydrogen bond accepting groups, and higher principal moment of inertia should express high adsorption on the mercury electrode.


Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2188
Author(s):  
Pingping Jiang ◽  
Pascal Boulet ◽  
Marie-Christine Record

Two-dimensional MX (M = Ga, In; X = S, Se, Te) homo- and heterostructures are of interest in electronics and optoelectronics. Structural, electronic and optical properties of bulk and layered MX and GaX/InX heterostructures have been investigated comprehensively using density functional theory (DFT) calculations. Based on the quantum theory of atoms in molecules, topological analyses of bond degree (BD), bond length (BL) and bond angle (BA) have been detailed for interpreting interatomic interactions, hence the structure–property relationship. The X–X BD correlates linearly with the ratio of local potential and kinetic energy, and decreases as X goes from S to Te. For van der Waals (vdW) homo- and heterostructures of GaX and InX, a cubic relationship between microscopic interatomic interaction and macroscopic electromagnetic behavior has been established firstly relating to weighted absolute BD summation and static dielectric constant. A decisive role of vdW interaction in layer-dependent properties has been identified. The GaX/InX heterostructures have bandgaps in the range 0.23–1.49 eV, absorption coefficients over 10−5 cm−1 and maximum conversion efficiency over 27%. Under strain, discordant BD evolutions are responsible for the exclusively distributed electrons and holes in sublayers of GaX/InX. Meanwhile, the interlayer BA adjustment with lattice mismatch explains the constraint-free lattice of the vdW heterostructure.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Deng-Xue Ma ◽  
Yao-Yao Wei ◽  
Yun-Zhi Li ◽  
Guo-Kui Liu ◽  
Qi-Ying Xia

The structural, relative stability, electronic, IR vibrational, and thermodynamic properties of asymmetric clusters (CH3FBN3)n (n = 1–6) are systematically investigated using density functional theory (DFT) method. Results show that clusters (CH3FBN3)n (n = 2–6) form a cyclic structure with a B atom and a Nα atom binding together. Five main characteristic regions are observed and assigned for the calculated IR spectra. The size-dependent second-order energy difference shows that clusters (CH3FBN3)3 and (CH3FBN3)5 have relatively higher stability and enhanced chemical inertness compared with the neighboring clusters. These two clusters may serve as the cluster-assembled materials. The variations of thermodynamic properties with temperature T or cluster size n are analyzed, respectively. Based on enthalpies in the range of 200–800 K, the formations of the most stable clusters (CH3FBN3)n (n = 2–6) from monomer are thermodynamically favorable. These data are helpful to design and synthesize other asymmetric boron azides.


2019 ◽  
Vol 33 (31) ◽  
pp. 1950386
Author(s):  
Vladimir Saleev ◽  
Alexandra Shipilova

The first-principles calculations of band gaps and bulk moduli of cesium lead halide perovskite solid solutions, [Formula: see text] and [Formula: see text], are performed at the level of general gradient approximation of the density functional theory. We use supercell approach for computational modeling of disordered systems, which gives a description of the properties of the structure baasing on the average over a set of multiple configurations, namely distributions of different species over a given set of atomic positions. The calculations were performed with the CRYSTAL14 program package. The dependence of the band gap and bulk modulus on the content [Formula: see text] are investigated over the whole range [Formula: see text].


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