title: Temperature-Dependent Emission Kinetics of Colloidal Semiconductor Nanoplatelets Strongly Modified by Stacking.
abstract: We systematically studied temperature-dependent emission kinetics in solid films of solution-processed CdSe nanoplatelets (NPLs) that are either intentionally stacked or nonstacked. We observed that the steady-state photoluminescence (PL) intensity of nonstacked NPLs considerably increases with decreasing temperature, whereas there is only a slight increase in stacked NPLs. Furthermore, PL decay time of the stacked NPL ensemble is comparatively much shorter than that of the nonstacked NPLs, and this result is consistent at all temperatures. To account for these observations, we developed a probabilistic model that describes excitonic processes in a stack using Markov chains, and we found excellent agreement between the model and experimental results. These findings develop the insight that the competition between the radiative channels and energy transfer-assisted hole trapping leads to weakly temperature-dependent PL intensity in the case of the stacked NPL ensembles as compared to the nonstacked NPLs lacking strong energy transfer. This study shows that it is essential to account for the effect of NPL stacking to understand their resulting PL emission properties.
authors.affiliation: Department of Electrical and Electronics Engineering, Department of Physics, UNAM - Institute of Materials Science and Nanotechnology, Bilkent University , Ankara 06800, Turkey.
authors.forename: Onur
authors.initials: O
authors.lastname: Erdem
authors.affiliation: Department of Electrical and Electronics Engineering, Department of Physics, UNAM - Institute of Materials Science and Nanotechnology, Bilkent University , Ankara 06800, Turkey.|Department of Physics, Abant Izzet Baysal University , Bolu 14280, Turkey.
authors.forename: Murat
authors.initials: M
authors.lastname: Olutas
authors.affiliation: Department of Electrical and Electronics Engineering, Department of Physics, UNAM - Institute of Materials Science and Nanotechnology, Bilkent University , Ankara 06800, Turkey.
authors.forename: Burak
authors.initials: B
authors.lastname: Guzelturk
authors.affiliation: Department of Electrical and Electronics Engineering, Department of Physics, UNAM - Institute of Materials Science and Nanotechnology, Bilkent University , Ankara 06800, Turkey.
authors.forename: Yusuf
authors.initials: Y
authors.lastname: Kelestemur
authors.affiliation: Department of Electrical and Electronics Engineering, Department of Physics, UNAM - Institute of Materials Science and Nanotechnology, Bilkent University , Ankara 06800, Turkey.|LUMINOUS! Center of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering, School of Physical and Mathematical Sciences, Nanyang Technological University , Nanyang Avenue, Singapore 639798, Singapore.
authors.forename: Hilmi Volkan
authors.initials: HV
authors.lastname: Demir