1. Observation of the full exciton and phonon fine structure in CdSe/CdS dot-in-rod heteronanocrystals
- Author
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Granados Del Águila, Andrés, Jha, Bhawana, Pietra, Francesca, Groeneveld, Esther, De Mello Donegá, Celso, Maan, Jan C., Vanmaekelbergh, Daniël, Christianen, Peter C M, Debye Institute, Sub Condensed Matter and Interfaces, Sub Soft Condensed Matter, Sub Physical and Colloid Chemistry, Condensed Matter and Interfaces, Debye Institute, Sub Condensed Matter and Interfaces, Sub Soft Condensed Matter, Sub Physical and Colloid Chemistry, and Condensed Matter and Interfaces more...
- Subjects
Materials science ,excitons ,Phonon ,acoustic phonons ,Exciton ,General Physics and Astronomy ,Physics::Optics ,Correlated Electron Systems / High Field Magnet Laboratory (HFML) ,magnetic fields ,Physics and Astronomy(all) ,optical phonons ,law.invention ,Condensed Matter::Materials Science ,nanocrystals ,Materials Science(all) ,law ,General Materials Science ,Emission spectrum ,core-shell heterostructure ,Engineering(all) ,fluorescence line-narrowing ,Condensed matter physics ,General Engineering ,Laser ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,Magnetic field ,Nanocrystal ,Light emission ,Excitation - Abstract
Light emission of semiconductor nanocrystals is a complex process, depending on many factors, among which are the quantum mechanical size confinement of excitons (coupled electron-hole pairs) and the influence of confined phonon modes and the nanocrystal surface. Despite years of research, the nature of nanocrystal emission at low temperatures is still under debate. Here we unravel the different optical recombination pathways of CdSe/CdS dot-in-rod systems that show an unprecedented number of narrow emission lines upon resonant laser excitation. By using self-assembled, vertically aligned rods and application of crystallographically oriented high magnetic fields, the origin of all these peaks is established. We observe a clear signature of an acoustic-phonon assisted transition, separated from the zero-phonon emission and optical-phonon replica, proving that nanocrystal light emission results from an intricate interplay between bright (optically allowed) and dark (optically forbidden) exciton states, coupled to both acoustic and optical phonon modes. more...
- Published
- 2014