The combination of a neuromorphic architecture and photonic computing may open up a new era for computational systems owing to the possibility of attaining high bandwidths and the low-computation-power requirements. Here, the demonstration of photonic neuromorphic devices based on amorphous oxide semiconductors (AOSs) that mimic major synaptic functions, such as short-term memory/long-term memory, spike-timing-dependent plasticity, and neural facilitation, is reported. The synaptic functions are successfully emulated using the inherent persistent photoconductivity (PPC) characteristic of AOSs. Systematic analysis of the dynamics of photogenerated carriers for various AOSs is carried out to understand the fundamental mechanisms underlying the photoinduced carrier-generation and relaxation behaviors, and to search for a proper channel material for photonic neuromorphic devices. It is found that the activation energy for the neutralization of ionized oxygen vacancies has a significant influence on the photocarrier-generation and time-variant recovery behaviors of AOSs, affecting the PPC behavior.

Despite intensive research on photochemical activation of sol–gel metal oxide materials, the relatively long processing time and lack of deep understanding of the underlying chemical courses have limited their broader impact on diverse materials and applications such as thin‐film electronics, photovoltaics, and catalysts. Here, in‐depth studies on the rapid photochemical activation of diverse sol–gel oxide films using various spectroscopic and electrical investigations for the underlying physicochemical mechanism are reported. Based on the exhaustive chemical and physical analysis, it is noted that deep ultraviolet‐promoted rapid film formation such as densification, polycondensation, and impurity decomposition is possible within 5 min via in situ radical‐mediated reactions. Finally, the rapid fabrication of all‐solution metal oxide thin‐film‐transistor circuitry, which exhibits stable and reliable electrical performance with a mobility of >12 cm2 V−1 s−1 and an oscillation frequency of >650 kHz in 7‐stage ring oscillator even after bending at a radius of <1 mm is demonstrated.

Incorporation of Zr into an AlOx matrix generates an intrinsically activated ZAO surface enabling the formation of a stable semiconducting IGZO film and good interfacial properties. Photochemically annealed metal-oxide devices and circuits with the optimized sol-gel ZAO dielectric and IGZO semiconductor layers demonstrate the high performance and electrically/mechanically stable operation of flexible electronics fabricated via a low-temperature solution process.

The electrical transport and chemical sensing properties of individual multisegmented Au-poly(3,4-ethylenedioxythiophene)(PEDOT)-Au nanowires have been investigated. Temperature dependent conductivity measurements show that different charge transport mechanisms influence these properties in two types of PEDOT nanowires. Charge transport in PEDOT/poly(4-styrenesulfonic acid) (PSS) nanowires is in the insulating regime of the metal-insulator transition and dominated by hopping, while PEDOT/perchlorate (CIO4) nanowires are slightly on the metallic side of the critical regime. The vapor sensing properties of individual nanowires to water and methanol reflect the fact that the two kinds of PEDOT nanowires operate in different transport regimes. Nanowires in the metallic transport regime show much greater sensitivity to vapor-phase analytes than those in which transport is dominated by hopping.

Fabricating electronic devices using multi-level photolithography provides excellent control of feature geometry and registration between layers (1), but each deposition step incorporates just one material, from a limited set, over the entire chip. Alternatively, device components such as nanowires can be synthesized from many different materials and even coated with biological molecules before assembling them onto a chip. However, it is still challenging to accurately position the various nanowires in different locations on the chip (2,3).We present a hybrid approach that uses forces generated by electric fields to direct different populations of biofunctionalized nanowires to specific regions of the chip while providing accurate registry between each individual nanowire and the photolithographic features within that region. We synchronized sequential injections of nanowires carrying different DNA sequences with a programmed, spatially confined electric-field profile that directs nanowire assembly. Nanowire-bound DNA was able to selectively bind complementary targets after assembly and device fabrication, which makes this process compatible with conventional integrated circuit manufacturing.DNA oligonucleotides complementary to sequences found in human pathogens were attached covalently to different batches of nanowires (8 μm long, ∼10 9 wires per ml) (4). Aliquots were sequentially injected across a dense two-dimensional array of photolithographically defined microwells superimposed across gaps separating guiding electrodes used for programmed assembly (Fig. 1A). Electric-field calculations with sinusoidal voltages applied between specific pairs of guiding electrodes showed that the field strength is highest in the microwells that span the biased electrodes and negligible elsewhere (Fig. 1B). These field gradients induced long-range dielectrophoretic forces that directed individual nanowires to the biased microwells in <1 min. Fields were shielded in occupied wells, preventing additional nanowires from entering. Electrostatic forces centered the wires across the gaps, and capillary forces pushed them against the sides of the wells; this fixed the position of nanowire tips and their pitch, respectively. After all batches were assembled, we generated an array of nanowire resonator devices (5) by forming contacts to each wire (Fig. 1C).In this proof of concept, we assembled nanowires carrying different DNA sequences into three separate columns. We used ∼300-nm-diameter wires, with a 20-nm SiO 2 shell to facilitate verification of DNA function by fluorescence. After device integration, the entire chip was