title: Size selective excitonic transition energies in strongly confined CdSe quantum dots.
abstract: We report on the synthesis of CdSe nanocrystal quantum dots (QDs) of different radii (R). Size dependent optical properties like increase in the confinement energy with decreasing radius for different excitonic transitions are studied. Different excitonic transitions are calculated from the second derivative of UV-vis absorption spectra of as synthesized CdSe QDs. The transitions are assigned to specific states by calculating the transition energies using effective mass approximation. A close matching of the transition energies with the experiment suggesting that the second derivative of the absorption spectra could provide a direct knowledge of the electronic transition for the direct band gap semiconductor quantum dots.
authors.affiliation: Centre for Advanced Materials (CAM), Indian Association for the Cultivation of Science, Jadavpur Kolkata 700032, India.
authors.forename: Umamahesh
authors.initials: U
authors.lastname: Thupakula
authors.forename: Ali Hossain
authors.initials: AH
authors.lastname: Khan
authors.forename: Jayanta Kumar
authors.initials: JK
authors.lastname: Bal
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Ariga
authors.forename: Somobrata
authors.initials: S
authors.lastname: Acharya