OPTICAL DETECTION of CADMIUM SELENIDE QUANTUM DOTS via ABSORPTION SPECTROSCOPY and TRANSMISSION ELECTRON MICROSCOPY

Quantum dots are tiny semiconductor nanocrystals. Their dimensions between about 2 and 10 nm. They have attracted much attention due to their unique electronic optical properties. These particles can be synthesized in a variety of ways. Synthesis methods quantum classified into top-down bottom-up. Top-down approach is fragmentation process bulk material. In contrast top-down, constructed from atoms molecules the material at bottom-up procedure. Ball milling, lithography, laser ablation arc-discharge some methods. However, chemical reduction, thermal decomposition, sol-gel ultrasonic spray pyrolysis this study, hot-injection synthesis method cadmium selenide which kind procedure will explained. Cadmium been grown hot solvent 259oC. Concentration dispersed toluene has adjusted by observing first exciton peak. First excitonic absorbance peak measured around 2.18 eV. Transmission electron microscope photo these growth shown. The average diameter found approximately 3.48 Lattice fringe spacing as ~0.35