Evaluation of structural, morphological, optical, and electrical properties of zinc oxide semiconductor nanoparticles with microwave plasma treatment for electronic device applications

Abstract

ZnO is an important II-IV n-type direct bandgap semiconductor material that has exhibited wide consideration due to its applications in optoelectronic devices. In the present investigation, untreated and plasma-treated ZnO NPs were fabricated by a sol-gel route and analyzed with XRD, Raman, UV-Vis spectra, and I–V characteristic techniques. To be used in electronic applications, the ZnO nanoparticles were subjected to a plasma treatment process to tune their optical, vibrational mode, structural and electrical properties. XRD confirmed the pure Wurtzite tetragonal phase crystalline nature of produced samples. The average crystalline size, lattice constant, unit cell volume, and porosity were found in the range of 3.81–4.68 nm, a = 3.217–3.323 Å and c = 2.032–2.178 Å, 5.662–11.274 Å3 and 7.09–5.03%, respectively. The Raman spectra revealed that the intensity of Raman bands was increased due to the increase in the vibrational amplitude and increase in force constants with the enhancement in grain size, these spectra results are in good agreement with XRD and reveal the purity of samples. The bandgap found reduced from 3.56 eV to 3.39 eV by plasma treatment. The electrical studies revealed that plasma treatment improves the electrical properties of ZnO NPs without producing any structural distortions. I–V characteristic curves confirmed that the conductivity was increased from 8.3 X 10−6 to 5.5 X 10−4 ℧ cm−1 on plasma treatment which caused an increase in leakage current. The improved structural, vibrational mode, optical and electrical properties of prepared ZnO NPs make them a suitable candidate for application in electronic devices.