Configurable switching behavior in polymer-based resistive memories by adopting unique electrode/electrolyte arrangement.

The difference in resistive switching characteristics by modifying the device configuration provides a unique operating principle, which is essential for both fundamental studies and the development of future memory devices. Here, we demonstrate the poly(methyl methacrylate) (PMMA)-based resistive switching characteristics using four different combinations of electrode/electrolyte arrangement in the device geometry. From the current-voltage (I-V) measurements, all the PMMA-based devices revealed nonvolatile memory behavior with a higher ON/OFF resistance ratio (∼105-107). Significantly, the current conduction in the filament and resistive switching behavior depend majorly on the presence of Al electrode and electrochemically active silver (Ag) element in the PMMA matrix. A trap-controlled space charge limited conduction (SCLC) mechanism constitutes the resistive switching in the Al/PMMA/Al device, whereas the current conduction governed by ohmic behavior influences the resistive switching in the Ag-including devices. The depth-profiling X-ray photoelectron spectroscopy (XPS) study evidences the conducting filament formation processes in the PMMA-based devices. These results with different conduction mechanisms provide further insights into the understanding of the resistive switching behavior in the polymer-based devices by simply rearranging the device configuration.

Hierarchical Doped Gelatin-Derived Carbon Aerogels: Three Levels of Porosity for Advanced Supercapacitors.

Nitrogen-doped graphene-based aerogels with three levels of hierarchically organized pores were prepared via a simple environmentally friendly process, and successfully tested in supercapacitor applications. Mesopores and macropores were formed during the aerogel preparation followed by carbonization and its chemical activation by potassium hydroxide (KOH). These mesopores and macropores consist of amorphous carbon and a 3D graphene framework. Thermal treatment at 700 °C, 800 °C, 900 °C in N2 atmosphere was done to etch out the amorphous carbon and obtain a stable N-doped 3D graphene. Specific capacitance values obtained from the electrochemical measurements are in the range of 232-170 F× g-1. The thus fabricated structures showed excellent cyclic stability, suggesting that these materials have potential as electrodes for solid asymmetric supercapacitors.

Institutions and poverty.

This study utilises eight alternative measures of institutions and the instrumental variable method to examine the impacts of institutions on poverty. The estimates show that an economy with a robust system to control corruption, an effective government, and a stable political system will create the conditions to promote economic growth, minimise income distribution conflicts, and reduce poverty. Corruption, ineffective governments, and political instability will not only hurt income levels through market inefficiencies, but also escalate poverty incidence via increased income inequality. The results also imply that the quality of the regulatory system, rule of law, voice and accountability, and expropriation risk are inversely related to poverty but their effect on poverty is via average income rather than income distribution.