Synthesis, Characterization and Optical Properties of CdSe and ZnSe Quantum Dots

This paper presents the synthesis of high quality, water soluble quantum dots of Cadmium Selenide and Zinc Selenide using solvothermal method. The size and morphology of quantum dots were analyzed from X-ray diffraction, transmission electron microscopy and high resolution transmission electron microscopy. These investigations show that particle size is in 2-5 nm range with cubic crystalline phase. Also effective mass approximation confirms the narrow size of nanoparticles. The functional groups attached and optical properties were analyzed from Fourier transform infrared spectroscopy, UV-visible spectroscopy, photoluminescence spectroscopy and micro-Raman spectroscopy respectively. The band gaps of 3.51 and 4.2 eV of mercapto free Cadmium Selenide and Zinc Selenide quantum dots, the photoluminescence blue shift and broadening of Raman spectrum further confirms the narrow size of particles.