Tunneling Across Semiconductor And Ferroelectric Heterostructures In The Presence Of External Bias

Abstract

Quantum tunneling phenomenon is an intriguing phenomenon that defies our classical newlineunderstanding of physics. It describes the process by which particles, such as electrons, newlinepass through a potential energy barrier that they classically shouldn t be able to newlineovercome due to insufficient energy. Quantum tunneling offers several advantages that newlinehave been harnessed in various technological applications i.e. Scanning tunneling newlinemicroscopes (STM), quantum computers, memory devices etc. Tunneling across various newlinesemiconductor heterostructures is a fundamental quantum mechanical process that has newlineseveral useful applications in modern electronics due to modulations in the electronic newlineproperties of heterostructures. Some of the applications include Resonant Tunneling newlineDiodes (RTDs), Quantum cascade lasers and high-frequency transistors etc. RTDs, due newlineto their resonant tunneling structure and Negative Differential Conductance (NDC) newlineregions in the I-V characteristics are capable of integrating with high-speed circuits, newlinenanoelectronics and THz oscillators. The measure of performance of RTD devices is newlinetermed as Peak-to-valley current ratio (PVCR), which can be enhanced by modulating newlinethe device parameters such as well width, barrier width, spacer layer width and doping newlineconcentration. newlineOur first work deals with the numerical optimization of GaAs/Al0.3Ga0.7As, newlineGaN/Al0.3Ga0.7N and In0.53Ga0.47As/AlAs Double barrier RTD devices in order to newlineachieve highest possible PVCR, based on device parameters, without compromising newlinepeak and valley current densities. With the help of Transfer Matrix Method (TMM), newlineexact Airy functions as solutions of Schrodinger s equation under an applied bias and newlineeffective-mass based boundary conditions, Transmission characteristics are determined newlineand tunneling current density is computed from transmission coefficients, using Tsu- newlineEsaki s current density formula in software MATHEMATICA. Based on these newlinecalculations, optimum well width and barrier width relations are proposed in terms of newlineeffective mass and barrier height.