Cu2+-Mn2+-Co-doped CdO nanocrystallites: comprehensive research on phase, morphology and optoelectronic properties

In this study, firstly cadmium hydroxide nanopowder was evolved by cost-effective wet chemical co-precipitation method. The transformation of nanocrystalline Cu2+-Mn2+-co-doped CdO occurred via thermal decomposition of the obtained hydroxide at 750 degrees C. The structural, optical and electrical behavior of nanocrystallites was analyzed by different complementary measuring tools. DTA of the as-prepared sample exhibited an endothermic peak at 240 degrees C attributed to crystallization. XRD analysis depicted a multiphase structure in the as-prepared sample, and pure rocksalt structure was obtained after annealing. Cu2+-Mn2+-co-doped cubic CdO has been achieved first time which was further confirmed by FTIR with various stretching and bending vibrations of Cd-O at 720, 625 and 460 cm(-1). SEM-TEM images demonstrated the brain-like morphology of different hexagonal and spherical nanocrystallites with an average size of similar to 35 nm. In addition, optical band gap energy was found in the range 2.14-2.44 eV by Tauc's plot. In photoluminescence results, emission spectra have many bands at 420, 480, 550 nm originated from excitonic transition, structural defects and oxygen vacancies, while intense peak at 450, 520 nm may be ascribed to Cu(2+)and Mn(2+)dopants, respectively. Hall measurements demonstrated that the Cu2+-Mn2+-co-doped CdO with a pure cubic phase has superior semiconducting behavior. The homogeneous codoping of Cu2+-Mn(2+)leads to efficient modification in structural, optical and electrical parameters of CdO which would make such materials attractive for semiconductor and photovoltaic industry, etc.