Quantum Confinement in CdTe Quantum Dots: Investigation through Cyclic Voltarnmetry Supported by Density Functional Theory (DFT)

Cyclic voltammetry study has been used as a tool to study the quantum confinement in oleic acid stabilized CdTe quantum dot dispersions. The band structure parameters, conduction band edge, valence band edge, and quasi-particle gap, have been estimated as a function of quantum dot size, ranging from ca. 2.4 to 4.7 nm and compared with the corresponding UV vis data. To support the experimental results, density functional theory (DFT) based calculations have been performed for passivated nonstoichiometric Cd-m, Te-n (m not equal n) clusters, using the projector augmented wave method. The computed HOMO-LUMO positions and their energy separations have been found to be in good agreement with the values obtained from UV-vis spectroscopy and cyclic voltammetry.