Thermoelectric, Electrochemical, & Dielectric Properties of Four ZnO Nanostructures

Abstract

In this work, we investigated the thermoelectric, electrochemical, and dielectric properties of four different ZnO morphologies, namely nanoribbons, nanorods, nanoparticles, and nanoshuttles. Temperature-dependent Seebeck coefficients were observed using thermoelectric measurements, which confirmed that all synthesized ZnO nanostructures are n-type semiconductors. The Van der Pauw method was applied to measure electrical conductivity, which was also used to calculate the thermal activation energy. Electrochemical properties were analyzed by cyclic voltammetry techniques under five different optical filters. Electrical conductivity of ZnO morphologies showed an increasing trend with increasing temperature. The highest electrical conductivity (1097.60 Ω−1m−1) and electronic thermal conductivity (1.16 ×10−4 W/mK) were obtained for ZnO nanorods at 425 K, whereas ZnO nanoshuttles carried the lowest electrical conductivity (1.10 ×10−4 Ω−1m−1) and electronic thermal conductivity (8.72 × 10−7 W/mK) at 325 K. ZnO nanorods obtained the maximum Power factor value in all temperature ranges. All nanostructures showed electro-catalytic performance with different optical filters. From impedance spectroscopy analysis, ZnO nanorods showed the highest dielectric constant at high frequencies (>1 MHz) at 2.02 ± 0.06, while ZnO nanoshuttles gave the highest dielectric constant at low frequencies (<100 Hz) at 9.69 ± 0.05. These results indicate that ZnO nanorods have the most favorable thermoelectric, electrochemical, and dielectric properties compared to all other ZnO morphologies.

Advancing Thermoelectric Materials: A Comprehensive Review Exploring the Significance of One-Dimensional Nano Structuring

“…Bui et al synthesised oxide (ZnO) NWs (NWs) with diameters ranging from 50 to 210 nm using CVD and investigated the diameter-dependent thermal transport, concluding that there is a significant reduction in thermal conductivity of (ZnO) NWs (NWs) compared to bulk ZnO due to increased phonon boundary scattering [ 253 ]. Rusiri et al (2022) investigated the effect of ZnO morphology, such as nanoribbons, nanorods, nanoparticles, and nanoshuttles, on the TE performance and found that the highest performance can be achieved using ZnO NRDs [ 254 ].…”

MIIM Rectenna with a Meta-lens for Enhanced IR Energy Scavenging at 28.3 THz

“…Also, the asymmetric configuration of Au-Al2O3-Cu2O-Cu shows superior characteristics among all compared configurations. The lesser difference of bandgap and electron affinities of used metals and insulators (see Table 2 [33][34][35][36]) for the symmetric metals case i.e. Au-Al2O3-Cu2O-Au configuration makes it less efficient.…”

Dielectric Property, AC Conductivity, and Electric Modulus Studies of Pristine and Green‐Synthesized ZnO Nanoparticles

“…For decades, zinc oxide (ZnO) nanoparticles (NPs) have attracted considerable interest of the research community in different areas of science and technology due to the fundamental importance as well as huge potentials for application of these materials in devices (e.g., optoelectronic, nanopiezotronics, nanogenerator, nanosensor, laser applications, high dielectric application, solar cells, and photocatalysis). [1][2][3][4][5][6][7][8][9][10][11] ZnO with wide direct bandgap energy (3.1-3.3 eV) and high excitation binding energy (60-100 meV) is a well-known II-VI n-type semiconducting material. [12] It crystallizes in a stable hexagonal wurtzite structure where the Zn and O atoms have highly ionic bonding.…”