Effects of changing Al mole fraction on the performance of an InGaAlAs-InP DBRTD

The effects of changing the InAlGaAs alloy composition in the contact, barrier and well layers of a double barrier resonant tunnelling diode (DBRTD), lattice-matched to the InP substrate, on the transmission curves and the peak-to-valley current ratio (PVCD) have been studied. A simple RTD model, in which the applied bias is assumed to drop across the double barrier region, is used in the simulation. The Airy function formalism is used to solve the Schrodinger equation in the structure and the transfer matrix method is used to calculate the transmission coefficient, which is then used to calculate the Tsu and Esaki tunnelling current. It is found that among all the structures studied, RTDs with In/sub 0.52/Al/sub 0.48/As barriers and In/sub 0.52/Al/sub 0.48/As well and contact have the best performance.