Preparation Of Cdte Quantum Dots And Its Preliminary Application

Quantum dots, so-called semiconductor nanometer crystal, have been paid more and more attention due to their unique optical and electrical properties. Especially in the field of biological detection, they have more extensive application prospects. Because of its light-emitting area easier to reach the near infrared region, CdTe quantum dots are expected to be applied in deep tissue imaging.In this paper, two different kinds of CdTe quantum dots were synthesized through High-temperature oil phase method and hydrothermal synthesis method and by controlling the experimental conditions, near infrared light-emitting quantum dots were synthesized, and a good foundation was laid for their use in Biological Detection. Specific contents are as follows:First,we successfully prepared CdTe quantum dots (QDs) by high-temperature oil phase method, which were high crystallization and monodisperse. And then, the influences of reaction time, reaction temperature and injection times on optical property of QDs had been discussed. Results show: with the increase of reaction time, the absorption and emission spectra of quantum dots were clearly red shifted, and the size grows larger; with the raise of reaction temperature, the absorption and emission spectra of quantum dots were clearly red shifted, and the size grows larger. To improve the chemical stability and QY, alloy quantum dots-CdTeSe were prepared through One-pot synthesis, which have a high QY and are more stable. This result can be explained that Se reduced the surface defect of CdTe quantum dots. Prepared CdTe quantum dots were used in QDs fluorescence microspheres, which could be applied as biochips.Second, water soluble CdTe quantum dots were successfully synthesized through hydrothermal synthesis route, which were high crystallization and monodisperse, and have carboxy group on their surface. We discussed the influences of reaction time, reactant concentration and ligand on optical property of QDs. The characterization results showed that: with the increase of reaction time, the absorption and emission spectra of quantum dots were clearly red shifted, and the size grows larger; With the growth of reactant concentration, the absorption and emission spectra of quantum dots were red shifted; Small ligand can stabilize the quantum dots better than bigger ones. Water soluble CdTe quantum dots can be used in immunofluorescent test directly, and lays a good foundation for their further use.By using multiple injection method the full width at half maximum (FWHM) of the photoluminescence (PL) peak was reduced by 10nm without depression of QDs'photoluminescence performance, and helps a lot for their application in multiplex detection.