Metal Insulator Metal Diode: A Potential Candidate for Energy Harvesting Applications.

Metal-Insulator-Metal (MIM) diodes used for infrared detection and frequency mixing since many decades and their development for energy harvesting applications in rectenna solar cell has accelerated a decade ago. In the horizon of these applications less complex fabrication methodology, accurate simulation methods and optimum material combination are required. Ultra-fast response of MIM diodes makes them a potential candidate for solar energy harvesting applications. Here in this work, the design and fabrication issues of MIM diode from simulation methodology based on insulating thickness properties to the fabrication methodology are discussed. MIM diode for Al-Al2O3-Ag combination is fabricated and characteristics such as I(V), asymmetry and non-linearity are reported.

Laser patterned, high-power graphene paper resistor with dual temperature coefficient of resistance.

Printing of electronic devices on a paper substrate using 2D graphene-based ink is an opening gate to innovative applications, where devices would be biodegradable, eco-friendly and can be disposed of with negligible impact on the environment. A resistor is a key element of electronic devices and their application area depends upon its power rating and temperature coefficient of resistance (TCR). In this work, in house developed graphene ink is successfully utilized to fabricate a paper-based resistor using a bar coating technique. Dimensional patterning with precise known values of resistance is achieved using a laser with freedom of shape and size which has been explored for the first time on a paper substrate. The resistor has potential to handle ∼7 W power at room temperature with capacity to withstand up to 200 V which is the highest among reported printed resistors. A dual, low and high TCR is observed, correspondingly in cold (173 K to 300 K) and hot (300 K to 373 K) temperature regions with an activation energy E a of ∼8 meV for the cold region which is 375 percent lower than the hot region (∼30 meV). The dual TCR behaviour is of great importance for application as a stable resistor up to room temperature, and as a thermistor above room temperature.