Kayaci, NilgunOzdemir, ResulKalay, MustafaKiremitler, N. BurakUsta, HakanOnses, M. Serdar2025-09-252025-09-2520221616-301X1616-3028https://doi.org/10.1002/adfm.202108675https://hdl.handle.net/20.500.12573/4357Ozdemir, Resul/0000-0002-7957-110X; Onses, Mustafa Serdar/0000-0001-6898-7700; Kiremitler, N. Burak/0000-0001-6065-4899; Kayaci, Nilgun/0000-0002-7988-8668; Kalay, Mustafa/0000-0002-3865-980XThe development of novel physically unclonable functions (PUFs) is of growing interest and fluorescent organic semiconductors (f-OSCs) offer unique advantages of structural versatility, solution-processability, ease of processing, and great tuning ability of their physicochemical/optoelectronic/spectroscopic properties. The design and ambient atmosphere facile fabrication of a unique organic light-emitting physically unclonable function (OLE-PUF) based on a green-emissive fluorescent oligo(p-phenyleneethynylene) molecule is reported. The OLE-PUFs have been prepared by one-step, brief (5 min) thermal annealing of spin-coated nanoscopic films (approximate to 40 nm) at a modest temperature (170 degrees C), which results in efficient surface dewetting to form randomly positioned/sized hemispherical features with bright fluorescence. The random positioning of molecular domains generated the unclonable surface with excellent uniformity (0.50), uniqueness (0.49), and randomness (p > 0.01); whereas the distinctive photophysical and structural properties of the molecule created the additional security layers (fluorescence profile, excited-state decay dynamics, Raman mapping/spectrum, and infrared spectrum) for multiplex encoding. The OLE-PUFs on substrates of varying chemical structures, surface energies and flexibility, and direct deposition on goods via drop-casting are demonstrated. The OLE-PUFs immersed in water, exposed to mechanical abrasion, and read-out repeatedly via fluorescence imaging showed great stability. These findings clearly demonstrate that rationally engineered solution-processable f-OSCs have a great potential to become a key player in the development of new-generation PUFs.eninfo:eu-repo/semantics/closedAccessData EncodingDewettingFluorescenceOrganic SemiconductorsPhysically Unclonable FunctionsArticle10.1002/adfm.2021086752-s2.0-85121501861