A computational model for prediction of electric properties of nanostructured Lanthanum doped ZnO for application in EMI Shielding
Oana T Nedelcu1*, Titus Sandu1, Mirela Suchea1,2*, Oana Brancoveanu1
1 National Institute for Research and Development in Microtechnologies IMT Bucharest, 126A, Erou Iancu Nicolae Street, 077190 Voluntari-Bucharest Romania
2 Center of Materials Technology and Photonics, School of Engineering, Hellenic Mediterranean University, 71410 Heraklion, Crete, Greece
Abstract:
ZnO doped with rare earth elements changes the electric properties by modifying the electronic structure and increasing the conductivity. Moreover, nanostructured ZnO can induce quantum confinement effects and modify the carrier mobility. In this way new functionalities can be initiated. In the present work, a preliminary computational model is proposed to predict the electric properties of doped ZnO:La obtained by electrospinning method followed by calcination. The material is intended to be used in coatings for electromagnetic shielding. The model includes geometrical reconstruction of nanostructured doped ZnO:La (0.1%-5%) in powder form based on morphology revealed by SEM characterization and on physical and numerical modelling with Finite Element Method (FEM) implemented in Comsol Multiphysics software package. According to SEM characterization results, the doping concentration induces a variation of aspect and size nanorods from the cylindrical shape of pure ZnO having 0.5 height/radius ratio to a value 10 of this ratio for maximum concentration (5%). The increasing aspect ratio follows the monotonicity of increasing of doping concentration. The numerical results were obtained by simulation using Electric Current module, frequency mode, of a representative elementary volume (REV) with boundary conditions in applied voltage between two opposite faces and periodicity between the other opposite pair of surfaces. The results show how the current density and complex permittivity vary with doping concentration by taking into account solely the modified morphology induced by doping.
Acknowledgments:
This research was partially by PNRR/2022/C9/MCID/I8 CF23/14 11 2022 contract 760101/23.05.2023 financed by the Ministry of Research, Innovation and Digitalization in “Development of a program to attract highly specialized human resources from abroad in research, development, and innovation activities” within the – PNRR-IIIC9-2022 - I8 PNRR/2022/Component 9/investment 8 and partially by National Core Project “Advanced research in micro-nano-electronic devices, photonics, sensors, and microsystems for societal applications – µNanoEl" Contract no 8N/03.01.2023 supported by Romanian Ministry of Education and Research.
Replies