Evaluating ZnO nanoparticle formations by ultraviolet photoluminescence microscopy

This work assessed individual widegap semiconductor nanoparticles using ultraviolet photoluminescence (PL) microscopy. ZnO nanoparticles having a bandgap energy of 3.4 eV were first synthesized with a variety of reaction times and then evaluated, employing a unique spectroscopic system. The resulting spectra were processed to show components related to an exciton and three types of defects. The nanoparticles formed in the early stage of the reaction process all exhibited the smallest exciton and largest defect PL intensities whereas the fully grown nanoparticles provided an intense exciton peak but the lowest defect-related emissions. The particles sampled in the central reaction stage showed good exciton intensity but the greatest variation of the component peaks. Individual nanoparticle assessments suggested variations in the local environment during the formation of these materials. Detailed examinations in this manner are expected to assist in fabricating identical nanomaterials for future semiconductor technologies.