Dual Synapses and Security Devices from Ternary C₆₀-Pentacene-TiO_2-x Nanorods Heterostructures

In the context of information explosion, neuromorphic and hardware-based security devices have garnered significant attention for their capacity to facilitate parallel computing and not be vulnerable to hacking, respectively. A demonstration of a dual photosynaptic (DPS) and physically unclonable function (PUF) devices characterized by ternary TiO_2-x nanorods (NRs)/Pentacene/C₆₀ heterostructure are simultaneously presented. For the DPS device, the ternary heterostructure leads to parallel-operating DPS characteristics: i) wavelength-dependent (WD) synapse and ii) stimulus-moment-dependent (SMD) synapse. Each synaptic characteristic demonstrates a remarkable degree of plasticity, which signifies a smooth transition from short-term potentiation (STP) to long-term potentiation (LTP). Moreover, The face recognition assessments have unveiled recognition rates of 83.3% for 2 operational modes. Notably, the DPS device maintains stable performance on the business card, even after a rigorous 49-day testing period and undergoing 1 000 bending cycles. Regarding the PUF device, the security keys with unique patterns are created due to random current distribution induced by placement-dependent doping effects of SnO₂ quantum dots (QDs). Moreover, near-ideal inter-hamming distances (inter-HDs), uniformities, and entropies are verified for all cryptographic keys. These findings introduce a pioneering concept of photonic synapses with their successful integration onto various substrates, including the hardware-based security PUF device.