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Article Citation - WoS: 4Citation - Scopus: 4Thermally Controlled Band Gap Tuning in Cuo Nano Thin Films for Optoelectronic Applications(indian Assoc Cultivation Science, 2024) Delice, S.; Isik, M.; Gasanly, N. M.Temperature dependency of band gap in CuO nano thin films has been investigated by virtue of transmission experiments at different temperatures. Structural and morphological characterization were achieved using X-ray diffraction (XRD) and scanning electron microscopy (SEM) measurements. Analysis on the XRD diffractogram revealed the presence of monoclinic structure for the CuO. Average crystallite size was determined as 17.8 nm. Absorption characteristics in between 10 and 300 K were presented in the wavelength range of 360-1100 nm. The band gap of the CuO was found to be similar to 2.17 eV at 300 K using Tauc and spectral derivative methods. This value increased to similar to 2.24 eV at 10 K. Both methods showed that the band gap extended with decreasing temperature. Temperature dependency of the band gap was studied using Varshni relation. The band gap at absolute temperature, variation of the band gap with temperature and Debye temperature were calculated as 2.242 +/- 0.002 eV, - 5.4 +/- 0.2 x 10(-4) eV/K and 394 +/- 95 K, respectively.Article Citation - WoS: 14Citation - Scopus: 18Traps distribution in sol-gel synthesized ZnO nanoparticles(Elsevier, 2019) Delice, S.; Isik, M.; Gasanly, N. M.The distribution of shallow traps within the sol-gel synthesized ZnO nanoparticles was investigated using thermoluminescence (TL) experiments in the 10-300 K temperature range. TL measurements presented two overlapped peaks around 110 and 155 K. The experimental technique based on radiating the nanoparticles at different temperatures (T-exc.) between 60 and 125 K was carried out to understand the trap distribution characteristics of peaks. It was observed that peak maximum temperature shifted to higher values and activation energy (E-t) increased as irradiating temperature was increased. The E-t vs. T-exc. presented that ZnO nanoparticles have quasi-continuously distributed traps possessing activation energies increasing from 80 to 171 meV. (C) 2019 Elsevier B.V. All rights reserved.Article Citation - WoS: 9Citation - Scopus: 9Temperature-Tuned Optical Bandgap of Al-Doped Zno Spin Coated Nanostructured Thin Films(Elsevier, 2022) Isik, M.; Gasanly, N. M.Al-doped ZnO (AZO) nanostructured thin films were produced by spin coating of AZO ink. The structural characteristics were determined by x-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. XRD plot showed well-defined and intensive diffraction peaks belonging to hexagonal crystal structure. AZO thin films were observed in the form of nanostructure with size varying generally between 20 and 30 nm in the SEM image. The room temperature bandgap energies of undoped and Al-doped ZnO nanostructured films were obtained as 3.32(7) and 3.35(3) eV, respectively. Temperature-tuned bandgap energy characteristics of AZO films were revealed applying transmission experiments by varying the sample temperature. The temperature-bandgap energy dependency was studied by Varshni and Bose-Einstein expressions and optical parameters of AZO films were revealed.
