resumo
Bioinspired self-assembled structures are increasingly important for a variety of applications ranging from drug delivery to electronic and energy harvesting devices. An important class of these structures is diphenylalanine microtubes which are potentially important for optical applications including light emitting diodes and optical biomarkers. In this work we present the data on their photoluminescent properties at low temperatures (down to 12 K) and discuss the origin of the emission in the near ultraviolet (UV) range seen earlier in a number of reports. UV luminescence increases with decreasing temperature and exhibits several equidistant lines that are assigned to zero-phonon exciton emission line and its phonon replicas. We infer that the exciton is localized on the defect sites and significant luminescence decay is due to thermal quenching arising from the carrier excitation from these defects and non-radiative recombination. (C) 2016 Elsevier B.V. All rights reserved.
palavras-chave
PEPTIDE NANOTUBES; NANOSTRUCTURES; NANOMATERIALS; NANOWIRES
categoria
Physics
autores
Nikitin, T; Kopyl, S; Shur, VY; Kopelevich, YV; Kholkin, AL
nossos autores
Andrei Kholkin
Investigador Jubilado
Svitlana Kopyl
Investigadoragradecimentos
The research was made possible by Russian Scientific Foundation (Grant 14-12-00812). The authors wish to thank Alexandre Botas, and Profs. Rute Ferreira and Luis Carlos for the help with photoluminescence measurements and fruitful discussions. Part of this work was developed in the scope of the project CICECO - Aveiro Institute of Materials (Ref. FCT UID/CTM/50011/2013), financed by national funds through the FCT/MEC and, when applicable, co-financed by FEDER under the PT2020 Partnership Agreement.