Abstract
Abstract The purpose of this study was to fabricate less toxic semiconductor nanocrystals to replace the serious toxic cadmium-containing materials. In this study, we divided the content into three parts. The first part was the fabrication and characterization of CdSe/ZnS core/shell semiconductor nanocrystals. In this part, we established a system, successfully synthesized the semiconductor core/shell structure, the diameters are from 3.6 nm to 6.9 nm and emission wavelengths are from 560 nm to 610 nm. Then, the calculated energy gaps were from 2.09 to 2.28 eV by using the absorption spectra, and using TEM to observe the morphology and confirm the particle size. To make sure the existence of core/shell, we used EPMA and EELS to confirm the distribution of element in this structure. In stoichiometry, we used EDS and ICP-AES to make quantification, the former is more easily to detect the element of shell due to it is a surface analysis method. The second part was the fabrication and characterization of the alternative materials, non-cadmium containing semiconductor nanocrystals, and we succeeded in synthesizing the wurtzite-ZnSe QDs. In addition, due to the difficulties of doping transition metals, we tried to find some reasonable reasons to explain the phenomenon. Finally, we designed a LED device by using spin-coating to discuss the emissive character and efficiency and found that the emissive efficiency was greatly related the surface coverage of emissive layer.