Development of electrical conduction with beryllium doping of CdO nanostructure thin Films

Abstract

The objective of the present investigation is to study the effect of beryllium doping on the structural, optical, and electrical properties of CdO, focusing on the improvement of carrier mobility (μ) that accompanied with high electrical conductivity and good optical transparency in the near-infrared region. Thus, nanocrystallite Be-doped CdO films were prepared by vacuum evaporation method. The characterisation of the samples was done by using X-ray diffraction (XRD), scanning electron microscope (SEM), absorption spectroscopy, and Hall measurements. The characteristic XRD patterns indicated that the prepared Be-doped CdO films were single phase of cubic CdO structure of highly [111] orientation. Scanning electron microscope analysis revealed that the studied CdO films were characterized with high-density threads (wooly structure) and the incorporation of beryllium ions modified that structure forming almost round grains. It was observed that the room temperature conductivity (σ) and mobility (μ) could be controlled through the level of beryllium doping. The utmost carrier mobility was found to be ∼130 cm 2 /Vs in ∼ 0.10% Be films maintaining a low electrical resistivity of ∼ 4.14×10-4 Ω cm and a good transparency of ∼ 80% in the NIR spectral region. The results demonstrate that beryllium doping in low concentration levels is a good enough dopant that might be used to improve the optoelectrical properties of CdO. Generally, the properties found can make CdO:Be films particularly interesting in application of optoelectronic devices, solar cells, and field of transparent conducting oxides (TCO).