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Direct and simple surface engineering of indium tin oxide (ITO) by appropriate Ar plasma treatment was used to induce the carrier injection hotspot effect, similar to reported indirect approaches based on the introduction of additional nanostructures on ITO. Surface characterization analyses and electric field simulations indicate the formation of small-sized and dense injection hotspots on the treated ITO. Efficient electron injection was achieved in both inverted organic light-emitting diodes and corresponding electron-only devices employing the treated ITO as bottom cathode. The present results show that, in addition to the electronic structure, the microscopic morphology at the contacts could also play a critical role in achieving efficient carrier injection in organic electronic/optoelectronic devices.

A hybrid memristor based on the bilayer structure of indium gallium zinc oxide (IGZO)/polyvinyl alcohol (PVA) is developed, which demonstrates device state updates in an analog manner with high reliability. The IGZO/PVA heterojunction is crucial for the realization of the memristive characteristics, presumably associated with oxygen ion redistribution across the IGZO/PVA interface. The hybrid memristor may act as an electronic synapse, being capable of emulating synaptic potentiation with good linearity, synaptic depression, and paired-pulse facilitation. It highlights potential applications of the oxide-polymer heterojunction in the exploration of neuromorphic devices.

Bidirectional modulation of synaptic weight lays the basis for learning and memory in the brain, and the development of brain‐inspired photonic synaptic devices is hindered by deficient light‐stimulated inhibition. In this report, a type of organic thin film neuromorphic devices with a planar two‐terminal architecture, featuring as the inhibitory regulation of synaptic weight over two orders of magnitude upon selective UV illumination is developed. The in situ monitoring on the floating electrode potential and the corresponding simulation results demonstrate the effect of cumulative hole trapping in the polymer electret layer, which modulates the device conductance in a nonvolatile manner. Remarkably, UV‐induced long‐term depression is accompanied by enhanced short‐term potentiation in the device that may preserve a stable level of total synaptic activities. The UV‐stimulated inhibition and the adaptive short‐term plasticity, as well as the ON and OFF responses to light in the organic photonic synaptic device, suggest its potential applications in photonic neuromorphic computing.