Photoacoustic spectroscopy as a non-destructive technique for optical properties measurements of nanostructures

Abstract

In this work, photoacoustic (PA) spectroscopy as a non-destructive technique has been effectively used to study the optical properties of nanostructures. Cadmium cobalt sulfide quantum dots (QDs) have been deposited onto TiO2 (Titania) electrodes using a successive ionic layer adsorption and reaction (SILAR) technique for different cycles (1 to 10). The surface morphology of the prepared photoanodes has been studied using a scanning electron microscope (SEM). The elemental properties have been investigated using an energy dispersive X-ray spectrometer. The optical properties have been measured using both PA and UV–vis. spectrophotometer. The energy band gap (Eg) of the prepared photoanodes has been tuned from 3.29 eV to 2.49 eV as the number of SILAR deposition cycles increases from 1 to 10. This increase in Eg is mainly attributed to the increase in the QDs' size and hence the quantum confinement effect.