Excess and Thermal Currents in Gallium Arsenide Esaki Diodes

Abstract

The exponential excess current and the thermal current in GaAs Esaki diodes have been studied in the temperature range 77° to 350°K. The exponential excess current is observable in a typical sample up to bias voltages of 1.2 V and 1.4 V at room and liquid nitrogen temperatures, respectively. The existence of an exponential excess current in such a wide bias range requires an almost uniform distribution of intermediate states throughout the energy gap in the vicinity of a junction. The lattice defects of a high concentration should be responsible for the intermediate states. The thermal current in GaAs Esaki diodes is believed to be a high-injection current but not the usual diffusion current.