Semiconductor nanoparticles are very useful for high efficiency quantum dot sensitized solar cell. Compound semiconductor such as CuInxGa(1-x)Se2 (CIGS) is attractive due to high absorption coefficient, which is toxic and expensive. Cu2ZnSnS4 (CZTS) is high absorption material and nontoxic. In this study, nanoparticles were successfully synthesized by laser ablation method using deionized water as solvent. Laser ablation in liquid is one of promising methods to obtain nanoparticle-dispersed solution. Raw material is irradiated with pulse laser beam. The nanoparticles were characterized by means of X-ray diffraction, Raman scattering, scanning electron microscopy (SEM), dynamic light scattering (DLS) and UVâvis spectroscopy.
After laser irradiation, the color of nanoparticle-dispersed solution was changed from transparent to brown. SEM images showed that the particle size was changed from micro-size to nanometer-size after laser ablation. DLS data revealed that the secondary particle size was the range from 30 nm to 200 nm. Increase in laser fluence increased the secondary particle size. According to Raman spectra measurement, the suitable laser fluence for preparation of nanoparticles has been proved. By-product would be created by laser process. UVâvis absorption spectra revealed that samples absorbed visible light and that the absorption was increased with the increase in irradiation time and laser fluence.
Keywords
- Compound Semiconductor
- Laser Ablation
- Nanoparticle