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The main focus of this study is to synthesize Mn-doped CdO nanopowder and explore its optoelectronic behavior via a temperature-dependent mechanism. Mn-doped cadmium hydroxide nanopowder is primarily evolved using essential precursors by co-precipitation. Nanocrystalline powder of Mn-doped cadmium oxide is acquired after thermal treatment of the corresponding hydroxides. Various characterization tools have been used to examine the prepared samples. In the differential thermal analysis (DTA), a sharp endothermic peak was observed at 190°C and confirmed the Mn-doped hexagonal Cd(OH)2 nanostructure. In most annealed samples (at 750°C), this structure was modified to almost spherical cadmium oxide (CdO) nanoparticles. The surface images of electron micrographs clearly expressed the fabrication of nanorod-type structure, and the presence of cadmium (Cd), manganese (Mn), oxygen (O) have been confirmed by energy dispersive spectroscopy (EDS). The band gap energy of these nanorod-like structures is obtained in the range 3.07 − 3.39 eV, and further photoluminescence (PL) results emphasized the broad bands in the blue-green region. Electrical characteristic curves inferred that the resistivity is reduced while current density is significantly increased using proper thermal treatment. Such semiconductor nanocrystallites can be utilized as a potential alternate of modern oxides with better conductivity and superior luminescence in the visible region. [ABSTRACT FROM AUTHOR]

This work reports about annealing time effect on structural and optical properties of pure and Dy 3 + -doped CeO2 nanocrystallites. The nanopowders with an average grain size 13–15 nm are successfully synthesized via a conducive and neoteric Pechini-type sol–gel technique. Surface morphology, composition, band gap and photoluminescence properties of the prepared samples are examined by multifarious characterization techniques like Rietveld refinement, FESEM, HRTEM, FTIR, UV–Vis spectroscopy and PL. The effects of annealing time on structural parameters including lattice parameter, bond distance, bond angle, strain, crystallite size and texture coefficient are computed for all prepared samples which are further ensured by Rietveld refinement. In absorption spectra, blue shift in the band gap of as-prepared samples has been observed due to well-known quantum size effect, however, red shift is noticed in further annealed samples. PL emission peaks are observed in violet, blue and green regions that are devoted to various defect levels and color centers such as F, F + , F + + , etc. It is suggested that defects like oxygen vacancies play vital role in tailoring the band gap of prepared samples and therefore enhance its utility in photonics and oxygen storage appliances. [ABSTRACT FROM AUTHOR]