In this work, we will discuss the optical properties of NiO nanoparticles that we have investigated recently by photoluminescence (PL) spectroscopy. In particular, we will show the blue-shifts of PL, originating from the electron-hole recombination of the self-trapped exciton (STE), observed in smaller-sized NiO nanoparticles. To explain the size effect in relating to the STE PL shift, a question has been raised on whether it is appropriate to apply him quantum confinement (QC) theory usually used for the Mott-Winner type excitons in semiconductors to wide band-gap material, such as silica. Variations in several parameters and their effects on the structural (crystal size and morphology) properties of nanoparticles were investigated. Characterizations were carried out by X-ray diffraction (XRD), scanning electron microscopy (SEM), thermal stability (TGA and DTA), solid state UV and solid state florescent (PL).
Musevi, S. J., Aslani, A., Motahari, H., & Salimi, H. (2016). Offer a novel method for size appraise of NiO nanoparticles by PL analysis: Synthesis by sonochemical method. Journal of Saudi Chemical Society, 20(3), 245–252. https://doi.org/10.1016/j.jscs.2012.06.009