High-k dielectric screen-printed inks for mechanical energy harvesting devices

There are a range of promising applications for devices that can convert mechanical energy from their local environment into useful electrical energy. Here, mechanical energy harvesting devices have been developed...

High-k Fluoropolymers Dielectrics for Low-Bias Ambipolar Organic Light Emitting Transistors (OLETs)

Organic light emitting transistors (OLETs) combine, in the same device, the function of an electrical switch with the capability of generating light under appropriate bias conditions. In this work, we demonstrate how engineering the dielectric layer based on high-k polyvinylidene fluoride (PVDF)-based polymers can lead to a drastic reduction of device driving voltages and the improvement of its optoelectronic properties. We first investigated the morphology and the dielectric response of these polymer dielectrics in terms of polymer (P(VDF-TrFE) and P(VDF-TrFE-CFE)) and solvent content (cyclopentanone, methylethylketone). Implementing these high-k PVDF-based dielectrics enabled low-bias ambipolar organic light emitting transistors, with reduced threshold voltages (<20 V) and enhanced light output (compared to conventional polymer reference), along with an overall improvement of the device efficiency. Further, we preliminary transferred these fluorinated high-k dielectric films onto a plastic substrate to enable flexible light emitting transistors. These findings hold potential for broader exploitation of the OLET platform, where the device can now be driven by commercially available electronics, thus enabling flexible low-bias organic electronic devices.

Enhancing Breakdown Voltage of a Ga2O3 Schottky Barrier Diode with Small-Angle Beveled and High-k Oxide Field Plate

To increase their breakdown voltage, Ga2O3 Schottky barrier diodes (SBDs) with a beveled field plate were designed based on TCAD platform simulations. The small-angle beveled field plate can effectively alleviate the electric field concentration effect. The breakdown voltage of Ga2O3 SBDs can reach 1217 V with the SiO2 dielectric and a small-angle (1°) beveled field plate. However, the breakdown mechanism is the early breakdown of the dielectric layer. TO further increase the breakdown voltage, the replacement of SiO2 with a high-k dielectric (Al2O3 and HfO2) can transfer the breakdown location into the Ga2O3 drift layer. By combining the beveled small-angle design and the high-k dielectric, the device demonstrates a Baliga’s figure of merit of 2.94 GW/cm2 and breakdown voltage of 3108V.

High-k Dielectric Double Gate Junctionless (DG-JL) MOSFET for Ultra Low Power Applications- Analytical Model

This paper describes the impression of low-k/high-k dielectric on the performance of Double Gate Junction less (DG-JL) MOSFET. An analytical model of the threshold voltage of DG-JLFET has been presented. Poisson’s equation is solved using the parabolic approximation to find out the threshold voltage. The effect of high-k on various performance parameters of N-type DG-JLFET is explored. The comparative analysis has been carried out between conventional gate oxide, multi oxide and high-k oxide in terms of Drain Induced Barrier Lowering (DIBL), threshold voltage, figure of merit (ION/IOFF) and sub-threshold slope (SS). The high-k oxide has shown superlative performance as compared to others. The results are further analyzed for various device structures. The DG-JLFET with HfO2 exhibits excellent attainment by mitigating the Short Channel Effects (SCEs). The significant reduction in off current makes the device suitable for ultra-low power applications. There is a 61.9 % and 34.29% improvement in the figure of merit and sub-threshold slope in the proposed device as compared to other devices. The simulation of DG-JLFET is carried out using the Silvaco TCAD tool.