Low-temperature photoluminescence in self-assembled diphenylalanine microtubes

authors	Nikitin, T; Kopyl, S; Shur, VY; Kopelevich, YV; Kholkin, AL
nationality	International
journal	PHYSICS LETTERS A
author keywords	Diphenylalanine; Self-assembly; Photoluminescence; Exciton
keywords	PEPTIDE NANOTUBES; NANOSTRUCTURES; NANOMATERIALS; NANOWIRES
abstract	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.
publisher	ELSEVIER SCIENCE BV
issn	0375-9601
year published	2016
volume	380
issue	18-19
beginning page	1658
ending page	1662
digital object identifier (doi)	10.1016/j.physleta.2016.02.043
web of science category	Physics, Multidisciplinary
subject category	Physics
unique article identifier	WOS:000373552000014