Simple method to determine series resistance and its temperature dependence in AlAs/GaAs/AlAs double barrier resonant tunnelling diodes

The author presents a simple empirical method to quickly determine the series resistance R_s of AlAs/GaAs/AlAs double barrier resonant tunnelling diodes, and its temperature dependence over the temperature range 198-295 K. At high voltage biases, the quantum well diode current-voltage characteristics were modelled with the empirical expression I_D approximately= exp (q(V_A-I_D.R_s)/kT). From this current-voltage relationship, R_s can be extracted from plots of the total resistance dV_A/dI_D against 1/I_D in the limit of 1/I_D to 0. The results showed that R_s decreased with temperature from 5.3 Omega at 198 K to 4.7 Omega at 295 K. R_s values extracted using the Nelder-Meade simplex algorithm agreed with those from the dV_A/dI_D against 1/I_D technique to within 10%.