Tailoring the Structural, Optical and Electrical Properties of Zinc Oxide Nanostructures by Zirconium Doping

Abstract

Owing to its low resistivity, high transmittance, and tunable optical band gap, ZnO is of great interest for optoelectronic applications. Herein, the sol–gel technique was used to synthesize un-doped and zirconium-doped zinc oxide (ZZO) nanostructures with different concentrations of Zirconium (Zr). X-ray diffraction (XRD), scanning electron microscope (SEM), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), UV-Vis spectroscopy, and photoluminescence (PL) measurements were used to investigate the influence of Zr doping on the structural, optical, and electrical properties of developed nanostructures. XRD and SEM confirmed the increase in crystallite size with increasing concentrations of Zr. Raman analysis indicated the presence of oxygen vacancies in synthesized nanostructures. UV-Vis spectroscopy illustrated the blue shift of band gap and red shift of the absorption edge for ZZO nanostructures with increasing concentrations of Zr. For the measurement of electrical properties, the spin-coating technique was used to deposit un-doped and Zr-doped ZnO layers of ~165 nm thickness. The four-probe-point (4PP) method illustrated that the doping of Zr caused a reduction in electrical resistance. Hall Effect measurements showed a high value, 3.78 × 1020 cm−3, of the carrier concentration and a low value, 10.2 cm2/Vs, of the carrier mobility for the Zr-doped layer. The high optical transmittance of ~80%, wide band gap of 3.51 eV, low electrical resistivity of 1.35 × 10−3 Ω·cm, and maximum carrier concentration of 3.78 × 1020 cm−3 make ZZO nanostructures one of the most promising candidates for the application of transparent conductive oxide (TCO) in optoelectronic devices.

Properties of spray pyrolysis deposited Zr-doped ZnO thin films and their UV sensing properties

“…Additionally, Rajkumar et al [37] observed a degradation in (002) intensity with increasing Zr content in sol-gel-deposited Zr:ZnO films. In contrast, Khan et al [38] did not observe any changes in diffraction peak intensities with increasing Zr content. These discrepancies may be attributed to variations in deposition parameters and techniques utilized across different studies.…”

“…The incorporation of Zr into the ZnO lattice offers a promising avenue for tailoring and enhancing the properties of thin films for various applications. One key advantage of Zr doping is the potential to improve the electrical conductivity and carrier concentration of ZnO thin films [30], making them more suitable for electronic and optoelectronic devices [31]. Additionally, Zr doping can help optimize material properties such as bandgap energy, optical transparency [31], and structural stability, enabling the development of highperformance thin film devices [32] with enhanced functionality and reliability.…”

Structural, Optical, Electrical and Photocatalytic Investigation of n-Type Zn2+-Doped α-Bi2O3 Nanoparticles for Optoelectronics Applications

“…Under the irradiation excitation, charge transfers from O 2 2p and Bi 6s orbitals to the conduction band of Bi, which is a 6p orbital, and the peak at 465 nm forms due to the recombination of free excitons after the de-excitation. , The band edge emission peak at 456 nm for pure α-Bi 2 O 3 nanoparticles (denoted as * in Figure ) shifted toward shorter wavelengths with increasing concentration of Zn 2+ ion in α-Bi 2 O 3 nanoparticles; e.g., for ZBO–D it occurs at 441 nm. The shifting of band edge emission peak toward the lower wavelength with increasing concentration of Zn 2+ is due to the improvement in energy of the band-to-band recombination according to the Burstein–Moss effect . In Zn 2+ -doped α-Bi 2 O 3 nanoparticles, the other three peaks were also recorded.…”

“…To investigate the effect of Zn 2+ ion on the electrical properties of α-Bi 2 O 3 nanoparticles, commonly used Hall measurements (Van der Pauw technique) were carried out to measure the carrier concentration, carrier type, resistivity, conductivity, and mobility of the fabricated nanoparticles . All of the synthesized nanoparticles showed n-type conductivity, and it was also observed that the conductivity and carrier mobility increase from 5.91 × 10 –6 S cm –1 for ZBO-A to 2.19 × 10 –5 S cm –1 for ZBO–D and 0.611 cm 2 /V·s for ZBO-A to 6.89 cm 2 /V·s for ZBO–D, respectively.…”

“…Since a few decades, scientific researchers have shown significant interest in metal oxides due to their environmentally friendly behavior, thermal stability, ferroelectric properties, mechanical strength, and biocompatibility. These metal oxide nanostructures have significant importance in a number of applications such as in nanomedicines, electrochemical sensors, supercapacitors, fluoresce, optoelectronics, and much more. − …”