Effect of transition metal co dopants on metal oxide semiconductor nanoparticles for optical limiting application

Abstract

Over the past decades, the advance in nanoscience and nanotechnology have played a very significant role in the field of nonlinear optics. Nanoparticles (NPs) are potential materials for various Nonlinear Optical (NLO) applications due to their ultrafast optical response, stronger two-photon absorption, higher laser induced damage threshold and higher third order NLO coefficient. So, the NLO based materials are having potential in next generation applications such as optical data storage device, optical power limiting, optical switching, optical information processing, photovoltaics, optical computing, opto-electronic, laser and nano-photonic devices. In the past few years, many researchers are much interested to develop nanostructure-based Metal Oxide Semiconductor (MOS) due to their distinct properties like optical, magnetic, electrical, better optical nonlinearity, fast response, size, high chemical and thermal stability. Among the various MOS, Copper Oxide (CuO), Zinc Oxide (ZnO) and Tin Oxide (SnO2) NPs are considered as a potential materials for their outstanding properties such as abundant, low-toxicity, high stability, low resistivity, high optical transparency, less expensive and easy availability. MOS NPs doped with various transition metals such as Al, Co, Cr, Ni, V, Fe, Mn, Zr, Zn, Cd and Mg is also a frequently utilized technique to increase their optical, electrical and magnetic characteristics. This kind of materials has been used for countless applications such as photocatalysis, lithium-ion battery, solar cell, sensors, optical power limiting, optical switching, magnetic storage devices, spintronics and nano-photonic devices. Hence, present investigation is aimed to synthesis the CuO NPs in pure and co-doped form (cadmium (Cd) - iron (Fe)) with 2 and 4 wt.% via employing simple co-precipitation method. PXRD pattern shows that there is no impurity in the single-phase monoclinic structure. The agglomeration of needle-like, flake-like and spherical-like morphologies for undoped and Cd-Fe (2 and 4 wt.%) co-doped CuO NPs are examined through SEM analysis. From UV-Vis DRS spectra, the obtained optical band gap of the synthesized materials was found to be 2.38, 2.62 and 2.77 eV for undoped and Cd-Fe (2 and 4 wt.%) co-doped CuO NPs. PL spectrum confirms the slight variation in emission wavelength compared to undoped CuO NPs. At different temperatures, dielectric property of synthesized samples is estimated by the dielectric constant, dielectric loss and ac conductivity measurements newline