title: Near-unity quantum yields of biexciton emission from CdSe/CdS nanocrystals measured using single-particle spectroscopy.
abstract: Biexciton photoluminescence (PL) quantum yields (Q(2X)) of individual CdSe/CdS core-shell nanocrystal quantum dots with various shell thicknesses are derived from independent PL saturation and two-photon correlation measurements. We observe a near-unity Q(2X) for some nanocrystals with an ultrathick 19-monolayer shell. High Q(2X)'s are, however, not universal and vary widely among nominally identical nanocrystals indicating a significant dependence of Q(2X) upon subtle structural differences. Interestingly, our measurements indicate that high Q(2X)'s are not required to achieve complete suppression of PL intensity fluctuations in individual nanocrystals.
authors.affiliation: Chemistry Division, Los Alamos National Laboratory, New Mexico 87545, USA.
authors.forename: Y-S
authors.initials: YS
authors.lastname: Park
authors.forename: A V
authors.initials: AV
authors.lastname: Malko
authors.forename: J
authors.initials: J
authors.lastname: Vela
authors.forename: Y
authors.initials: Y
authors.lastname: Chen
authors.forename: Y
authors.initials: Y
authors.lastname: Ghosh
authors.forename: F
authors.initials: F
authors.lastname: García-Santamaría
authors.forename: J A
authors.initials: JA
authors.lastname: Hollingsworth
authors.forename: V I
authors.initials: VI
authors.lastname: Klimov
authors.forename: H
authors.initials: H
authors.lastname: Htoon