Synthesis, Characterization, and Electronic Properties of ZnO/ZnS Core/Shell Nanostructures Investigated Using a Multidisciplinary Approach

Abstract

ZnO/ZnS core/shell nanostructures, which are studied for diverse possible applications, ranging from semiconductors, photovoltaics, and light-emitting diodes (LED), to solar cells, infrared detectors, and thermoelectrics, were synthesized and characterized by XRD, HR-(S)TEM, and analytical TEM (EDX and EELS). Moreover, band-gap measurements of the ZnO/ZnS core/shell nanostructures have been performed using UV/Vis DRS. The experimental results were combined with theoretical modeling of ZnO/ZnS (hetero)structures and band structure calculations for ZnO/ZnS systems, yielding more insights into the properties of the nanoparticles. The ab initio calculations were performed using hybrid PBE0 and HSE06 functionals. The synthesized and characterized ZnO/ZnS core/shell materials show a unique three-phase composition, where the ZnO phase is dominant in the core region and, interestingly, the auxiliary ZnS compound occurs in two phases as wurtzite and sphalerite in the shell region. Moreover, theoretical ab initio calculations show advanced semiconducting properties and possible band-gap tuning in such ZnO/ZnS structures.

Mechanical properties and behavior of the Ti–45Nb alloy subjected to extreme conditions

“…A multidisciplinary approach was employed to study the structure and properties of the investigated Ti-45Nb system. 39,40 Crystal structure prediction (CSP) was carried out consisting of a combination of two search methods, including data mining (DM) and evolutionary algorithms (EA), where the final structure optimizations were conducted utilizing ab intio density functional theoretical (DFT) calculations. 41,42 DM-based searches were initially performed by considering crystal structures classified in the Strukturbericht and ICSD databases, 43,44 and this was followed by the incorporation of structures obtained from EA searches implemented in the XtalOpt program.…”

Structures, Phase Stability, Amorphization, and Decomposition of V6O13 at High Pressures and Temperatures: Synthesis of Rutile-Related V0.92O2

“…Density functional theory (DFT) calculations were carried out using the local density approximation (LDA) with the Perdew–Zunger (PZ) correlation functional and generalized gradient approximation (GGA) with the PBE (Perdew, Burke, and Ernzerhof) functional . Additionally, the hybrid HSE06 (Heyd–Scuseria–Ernzerhof) exchange–correlation functional was utilized, as it is useful to choose several different ab initio methods, to evaluate the quantitative validity of the results. , An all-electron basis set based on the Gaussian-type orbitals was applied in the case of vanadium V_86-411d31G_harrison_1993 and a modified O_8-411_towler_199 basis set , for oxygen. The symmetries of all structure candidates found on the energy landscape were determined using the SFND and RGS algorithms, while duplicate structures were discarded using the CMPZ algorithm within the KPLOT software …”

Comparative study by simulation betweentwo structures CdS/CZTS and ZnS/CZTS via SCAPS-1D software

“…With bandgap energies of about 3.3 and 3.7 eV, respectively, zinc oxide ZnO and zinc sulfide (ZnS) are a priori very suitable materials for such applications [17]. Given our interest in the effect of temperature on the improvement of solar cell performance [18], it would be interesting to introduce the concept of coefficient of thermal expansion which has an impact on the durability of thin film solar cells [19].…”