Reconfigurable Electronic Physically Unclonable Functions Based on Organic Thin‐Film Transistors with Multiscale Polycrystalline Entropy for Highly Secure Cryptography Primitives

Abstract

In this study, organic thin-film transistors (OTFTs) are investigated as a promising platform for cost-effective, reconfigurable, and strong electronic physically unclonable functions (PUFs) for highly secure cryptography primitives. Simple spin-casting of solution-processable small-molecule organic semiconductors forms unique and unclonable fingerprint thin films with randomly distributed polycrystalline structures ranging from nanoscale molecular orientations to microcrystalline orientations, which provides a stochastic entropy source of device-to-device variations for OTFT arrays. Blending organic semiconductors with polymer materials is a promising strategy to improve the reliability of OTFT-based PUFs. Studies on the relationship between the phase-separated polycrystalline microstructure of organic semiconductor/polymer blend films and PUF characteristics reveal that the 2D mosaic microcrystalline structure of organic semiconductors in the vertically phase-separated trilayered structure enables the implementation of OTFT-based PUFs that simultaneously satisfy the requirements of being unclonable and unpredictable, with reliable cryptographic properties. The inherent multiscale randomness of the crystalline structure allows random distribution in OTFT-based PUFs even with various channel dimensions. The secret bit stream generated from the OTFT-based PUF developed in this study is reconfigurable by simply changing the gate bias, demonstrating the potential to counter evolving security attack threats.

Heteronanostructured Field-Effect Transistors for Enhancing Entropy and Parameter Space in Electrical Unclonable Primitives

“…In this respect, electrical PUFs using non-silicon nanomaterials have been actively studied. − A variety of nanomaterials as entropy sources have been employed in different types of electronic devices, including transistors, FETs, resistors, and memristors (Table S1). Notable constituent nanomaterials include poly­[(2,5-bis­(2-octyldodecyl)-3,6-bis­(thien-2-yl)-pyrrolo­[3,4- c ]­pyrrole-1,4-diyl)- co -(2,2′-(2,1,3-benzothiadiazole)]-5,5′-diyl)] (PODTPPD-BT), 2,8-difluoro-5,11-bis­(triethylsilylethynyl) anthradithiophene (diF-TESADT), indium oxide, indium tin oxide (ITO), silicon nanowires, propyl pyridinium lead iodide (PrPyr­[PbI 3 ]), hafnium­(IV) oxide, , Ta/CoFeB/MgO, germanium–antimony–tellurium (GaSbTe), poly­(styrene- b -methyl methacrylate) and hydroxyl-terminated P­(S-r-MMA) random copolymer, a mixture of octadecyltrichlorosilane and 1 H ,1 H ,2 H ,2 H -perfluorodecyltriethoxysilane (ODTS/PFOTES), carbon nanotubes (CNTs), ,,, and graphene. , However, these electrical PUFs based on nanomaterials possess a restricted parameter space, often limited to a single challenge–response pair.…”

“…Insufficient randomness with low entropy is often associated with output responses that follow a Gaussian distribution in a predictable manner. A single challenge–response pair in the existing transistor-based electrical PUFs using 2D TMDCs increases vulnerability to external attacks; field effect transistor (FET)-based PUFs using bare MoS 2 or WS 2 are intrinsically disadvantaged to enhance the parameter space, due to the limited measurements of gate voltage and drain current. ,,− It should be noted that an enhanced parameter space is of paramount importance in deployable and scalable PUFs. − Unfortunately, other electrical PUFs using nanomaterials and nanostructures − have a limited parameter space (see Table S1 of Supporting Information for comprehensive comparisons).…”

Ultradurable Embedded Physically Unclonable Functions

“…Motivated by the accelerating needs of encoded surfaces in anticounterfeiting and authentication, a diverse range of processes and materials have been recently explored for generation of PUFs. Quantum dots, − perovskite nanocrystals, luminescent materials, , plasmonic nanoparticles, − 2D materials, organic semiconductors, graphene, food-grade starch, self-wrinkling materials, , self-assembly of polymers, light-emitting organic molecules, electronic fingerprints, laser-induced carbonization, and polymeric particles are good examples to recent reports. The rich menu of materials proposed for PUF applications provides viable options for the vastly diverse needs of these applications.…”

In-depth theoretical analysis of the influence of an external electric field on charge transport parameters

“…1–6 Organic semiconductors (OSCs) have been greatly developed over the past few decades to harness these advantages. With the rapid development of high-performance OSC devices, organic materials are widely used in organic field-effect transistors (OFETs), 7,8 organic thin-film transistors (OTFTs), 9,10 organic light-emitting transistors (OLETs), 11,12 sensors, 13 flexible displays, 14 and wearable electronic devices. 4,15,16…”