ABSTRACT Metamaterials‐based nano‐resonators have been extensively studied due to their precise controllability for tuning electromagnetic waves, while it is difficult to map the effects of resonating‐light on electrical‐transport. Here, conductivities and the effects of charge‐traps with nanoscale resolutions are mapped in Ge 2 Sb 2 Te 5 (GST)‐based nano‐resonator under resonant excitations. In this strategy, a high electric‐field out of surface‐plane is applied through a conducting nano‐probe, and the probe scans to induce a phase‐transition. Results implicate an insulating‐to‐conducting‐phase transition induced by electric‐field, due to the formation of filament‐like conducting‐paths. Utilizing contrasting electrical and optical properties of conducting‐ and insulating‐phases, nano‐resonators are fabricated on the surface of GST. Then, plasmonic‐conductivities and the effects of charge‐trap in nano‐resonators are mapped. Nano‐resonators with linear‐gratings show plasmonic photocurrent upon illumination at selective‐wavelengths depending on grating‐elements. Contrarily, square‐shaped nano‐resonators effectively produce plasmonic effects on a broad wavelength range due to the large number of available modes, as evident from plasmonic‐wave simulations. Importantly, plasmonic effects prohibit the re‐trapping of carriers, resulting in dramatically low trap densities. Moreover, simulation shows that plasmonic effects are pronounced at short‐wavelengths, providing high plasmonic‐conductivities and low charge‐trap densities. The mapping of plasmonic‐transport properties can have significant impacts on basic research and applications of phase‐change material‐based‐plasmonic devices.

a conducting probe to directly map the charge-trap densities and conductivities with a nanoscale resolution. The results showed that edge regions had one-dimensional characteristics with higher conductivities (two orders) and lower charge-trap densities (four orders) than those of flat surface regions where their conductivities and charge-traps were dominated by bulk effects. Additionally, edges showed an enhanced conductivity with an elevated electric field, possibly due to the creation of new topological states by stronger spin-Hall effects. Importantly, we observed ultra-high photoconductivity predominantly on edge regions compared with that of flat surface regions, which was attributed to the excitation of edge-state carriers by light. Since our method provides an important insight into the charge transport in topological insulators, it could be a significant advancement in the development of error-tolerant topotronic devices.

transport behavior, respectively. Interestingly, semiconducting CNT networks also exhibited a gradual transition from a diffusive to a ballistic transport behavior as the CNT mobility was increased by reaching the on-state with negative gate biases. The mapping of the cross-patterned CNT network showed that metallic CNT electrodes could achieve a good electrical contact with semiconducting CNTs without high contact resistance regions. Since this method allowed one to map versatile charge transport properties such as mobility, conductivity, and charge trap density, it can be a powerful tool for basic research about charge transport phenomena and practical device applications.

ABSTRACT Metamaterials‐based nano‐resonators have been extensively studied due to their precise controllability for tuning electromagnetic waves, while it is difficult to map the effects of resonating‐light on electrical‐transport. Here, conductivities and the effects of charge‐traps with nanoscale resolutions are mapped in Ge 2 Sb 2 Te 5 (GST)‐based nano‐resonator under resonant excitations. In this strategy, a high electric‐field out of surface‐plane is applied through a conducting nano‐probe, and the probe scans to induce a phase‐transition. Results implicate an insulating‐to‐conducting‐phase transition induced by electric‐field, due to the formation of filament‐like conducting‐paths. Utilizing contrasting electrical and optical properties of conducting‐ and insulating‐phases, nano‐resonators are fabricated on the surface of GST. Then, plasmonic‐conductivities and the effects of charge‐trap in nano‐resonators are mapped. Nano‐resonators with linear‐gratings show plasmonic photocurrent upon illumination at selective‐wavelengths depending on grating‐elements. Contrarily, square‐shaped nano‐resonators effectively produce plasmonic effects on a broad wavelength range due to the large number of available modes, as evident from plasmonic‐wave simulations. Importantly, plasmonic effects prohibit the re‐trapping of carriers, resulting in dramatically low trap densities. Moreover, simulation shows that plasmonic effects are pronounced at short‐wavelengths, providing high plasmonic‐conductivities and low charge‐trap densities. The mapping of plasmonic‐transport properties can have significant impacts on basic research and applications of phase‐change material‐based‐plasmonic devices.

a conducting probe to directly map the charge-trap densities and conductivities with a nanoscale resolution. The results showed that edge regions had one-dimensional characteristics with higher conductivities (two orders) and lower charge-trap densities (four orders) than those of flat surface regions where their conductivities and charge-traps were dominated by bulk effects. Additionally, edges showed an enhanced conductivity with an elevated electric field, possibly due to the creation of new topological states by stronger spin-Hall effects. Importantly, we observed ultra-high photoconductivity predominantly on edge regions compared with that of flat surface regions, which was attributed to the excitation of edge-state carriers by light. Since our method provides an important insight into the charge transport in topological insulators, it could be a significant advancement in the development of error-tolerant topotronic devices.

transport behavior, respectively. Interestingly, semiconducting CNT networks also exhibited a gradual transition from a diffusive to a ballistic transport behavior as the CNT mobility was increased by reaching the on-state with negative gate biases. The mapping of the cross-patterned CNT network showed that metallic CNT electrodes could achieve a good electrical contact with semiconducting CNTs without high contact resistance regions. Since this method allowed one to map versatile charge transport properties such as mobility, conductivity, and charge trap density, it can be a powerful tool for basic research about charge transport phenomena and practical device applications.

devices achieved higher mobility, more positive threshold voltage, and improved bias stability, confirming reduced deep-trap activity and enhanced charge-transport uniformity. This work establishes a direct link between structural ordering, local trap-depth modulation, and macroscopic electrical performances of crystalline oxide channels.

environments, respectively. Moreover, it could discriminate similar floral odorants with a single-carbon-atomic resolution. Notably, this device allowed us to diagnose chalkbrood infection directly from honey bee larvae. In this respect, our bioelectronic nose can be a powerful tool as on-site assessment platforms and thus provide broad opportunities for basic studies on insect olfactory systems and applications in agricultural industries.

, indicating that localized traps near the band edges effectively reduce the bandgaps. Our strategy enables direct mapping of nanoscale photoconductive properties and their quantitative correlations, providing a powerful tool for both fundamental research and practical applications in optoelectronic devices.