Time-resolved photoluminescence study of CdSe/CdMnS/CdS core/multi-shell nanoplatelets

• Main Authors: Murphy, J. R., Zhang, P., Norden, T., Thomay, T., Cartwright, A. N., Demir, Hilmi Volkan, Petrou, A., Delikanli, Savas, Scrace, T.
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: English
• Published: 2016
• Subjects: Photoluminescence; Polarization
• Online Access: https://hdl.handle.net/10356/81969; http://hdl.handle.net/10220/41083
• Institution: Nanyang Technological University

We used photoluminescence spectroscopy to resolve two emission features in CdSe/CdMnS/CdS and CdSe/CdS core/multi-shell nanoplatelet heterostructures. The photoluminescence from the magnetic sample has a positive circular polarization with a maximum centered at the position of the lower energy feature. The higher energy feature has a corresponding signature in the absorption spectrum; this is not the case for the low-energy feature. We have also studied the temporal evolution of these features using a pulsed-excitation/time-resolved photoluminescence technique to investigate their corresponding recombination channels. A model was used to analyze the temporal dynamics of the photoluminescence which yielded two distinct timescales associated with these recombination channels. The above results indicate that the low-energy feature is associated with recombination of electrons with holes localized at the core/shell interfaces; the high-energy feature, on the other hand, is excitonic in nature with the holes confined within the CdSe cores.