Asad Mahmood

High-k Polymer Nanocomposites for Energy Storage Applications

High dielectric (high-k) polymer nanocomposites that can electrostatically store energy are widely used in electronics and electric power systems due to their high breakdown strengths (Eb), durability, and ability to configure in various shapes. However, these nanocomposites suffer from a limited working temperature regime, thus limiting their extreme applications, such as hybrid and electric vehicles, aerospace power electronics, and deep ground fuel exploration. Furthermore, the Eb and the electric displacement (D) of polymer nanocomposites must be simultaneously enhanced for high-density capacitor applications, which prove to be difficult to modify concurrently. This chapter thoroughly reviews (investigates) the recent developments in the high-k polymer nanocomposites synthesis, characterization, and energy storage applications. Consequently, the aim of this chapter is to provide an overview of the novel developmental strategies in order to develop high-dielectric nanocomposites perovskite ceramics that can be incorporated in high-energy-density (HED) applications.

Investigation of the effect of gate voltage on the performance of organic bulk hetero-junction based phototransistor

In this work, we have investigated the effect of gate voltage on the performance of poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C61-butyric acid methylester (PCBM) bulk hetero-junction based organic phototransistor. Transistor was fabricated in MESFET configuration with top gate and bottom drain-source electrodes on glass substrate. Active layer showed Schottky type contact with Gate electrode and Ohmic contact with Drain-Source electrodes. Current-Voltage (I-V) characteristics of the device were studied under dark and UV-Vis illumination. Active layer of the device has shown p-type and ambipolar properties under dark and UV-Vis illumination, respectively. Drain to source current of the phototransistor was found dependent on the illumination intensity and gate to source voltage. Photo sensitivity and responsivity values of the device were found to decrease exponentially with the increase of gate voltage. Photo sensitivity and responsivity values of the device were found equal to 11 and 0.024 A/W, respectively, at 90mW/cm2 UV-Vis illumination intensity and 0 gate voltage.