Role of the thermal regime in the defect formation of zinc oxide nanostructures prepared by the thermal decomposition process
Author:
Katekaew Panuwat1, Prasatkhetragarn Anurak23, Sirirak Reungruthai3, Boonruang Chatdanai45, Klinbumrung Arrak23
Affiliation:
1. Scientific Instrument and Product Standard Quality Inspection Center (SIPQC) , University of Phayao , Phayao , Thailand 2. Unit of Excellence on Advanced Materials for Sensors , University of Phayao , Phayao , Thailand 3. School of Science , University of Phayao , Phayao , Thailand 4. Center of Excellence in Materials Science and Technology , Chiang Mai University , Chiang Mai , Thailand 5. Faculty of Science , Chiang Mai University , Chiang Mai , Thailand
Abstract
Abstract
The intrinsic defect of ZnO depicts a crucial role in the charge transfer owing to the suppression of the exciton recombination, exhibiting superior semiconducting performance. In this study, the intrinsic defect of ZnO nanostructures prepared by direct thermal activation of 300–900 °C was investigated. X-ray diffraction (XRD) was employed to analyze phase, crystallite size, Zn–O bond length, and dislocation density. The relation of Williamson–Hall (W–H) was used to calculate crystallite size and micro-strain. The atomic coordination was approximated through the Rietveld method. Morphology and crystal growth investigation was carried on by scanning electron microscope (SEM) and tunneling electron microscope (TEM), exhibiting rod-like nanostructures transform to oval shape particle with high residual strain when increasing calcination temperature, exhibiting the crystal growth direction of (101). Specific surface and pore analysis reveals a significant value corresponding to SEM analysis. Fourier transform infrared spectroscopy (FT-IR) detected Zn–O stretching vibration bands, presenting a notable increase in the intensity when heat at 600 °C. Relating to the thermal regime, energy bandgap (Eg) was found to be 3.41–3.50 eV as increasing heat treatment temperatures. Photoluminescence (PL) was applied to determine intrinsic defects through emissive spectra. The surface charge was determined through the zeta potential measurement. The photo-induced dye degradation was measured to understand the effect of the defect in semiconductors. The X-ray photoelectron spectroscopy (XPS) confirms the wurtzite structure appearance, including the intrinsic defects. The observed intrinsic defects are discussed, associating with the structural constants, emissive spectra, cationic dye degradation, and binding energy.
Funder
Chiang Mai University
Publisher
Walter de Gruyter GmbH
Subject
Physical and Theoretical Chemistry
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