title: Time- and polarization-resolved optical spectroscopy of colloidal CdSe nanocrystal quantum dots in high magnetic fields.
abstract: In an effort to elucidate the spin (rather than charge) degrees of freedom in colloidal semiconductor nanocrystal quantum dots, we report on a series of static and time-resolved photoluminescence measurements of colloidal CdSe quantum dots in ultrahigh magnetic fields up to 45 T. At low temperatures (1.5-40 K), the steady-state photoluminescence (PL) develops a high degree of circular polarization with applied magnetic field, indicating the presence of spin-polarized excitons. Time-resolved PL studies reveal a marked decrease in radiative exciton lifetime with increasing magnetic field and temperature. Except for an initial burst of unpolarized PL immediately following photoexcitation, high-field time-resolved PL measurements reveal a constant degree of circular polarization throughout the entire exciton lifetime, even in the presence of pronounced exciton transfer via Förster energy transfer processes.
authors.affiliation: National High Magnetic Field Laboratory and Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: Madalina
authors.initials: M
authors.lastname: Furis
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Hollingsworth
authors.forename: Victor I
authors.initials: VI
authors.lastname: Klimov
authors.forename: Scott A
authors.initials: SA
authors.lastname: Crooker