Research Information System
16th NANOSCIENCE & NANOTECHNOLOGY CONFERENCE, Ankara, Turkey, 5 - 08 September 2022, pp.376
Anti-counterfeiting and data security applications require
design and development of novel materials and methods for encoding information.
[1] Physically unclonable functions (PUFs) has been introduced as a new
approach in fabrication of encoded surfaces . PUFs are composed of complex
structures embodied by stochastic mechanisms. The inherently random responses
of PUFs makes the replication of encoded surfaces impossible by third parties
or even by the manufacturer itself [2,3]. Fluorescent compounds attract great
attention, because of the simple and fast authentication [4]. In this study, we
will present fabrication of organic light-emitting physically unclonable
functions (OLE-PUFs) using fluorescent organic semiconductors (f-OSCs). The
formation of random domains via surface dewetting of thin films of f-OSCs is
the basis of our approach. The OLE-PUF fabrication process consists of
deposition of f-OSC and thermal annealing as short as 5 minutes at a modest
temperature (120 to 170 C). Depending on annealing temperature and film
thickness, bright and hemispherical random features with different properties
are formed on the surface by various transport mechanisms. Thanks to unique
photoluminescence and chemical properties of the f-OSC molecule and the random
positions of these hemispherical features, multi-layered security measures are
established. Multiple-security layer can be incorporated to OLE-PUFs using
unique fluorescence profile, excited-state decay dynamics, and Raman spectrum.
The OLE-PUFs can be formed on substrates of different chemistry, surface
wetting property and rigidity. The drop-casting enables direct deposition on
goods with minimal material consumption. OLE-PUFs are highly stable against
external effects such as water, sand, UV-light and temperature [5].