Current—voltage characteristics of connecting tunnel diodes at temperature heating up to 80°C

Investigations of the temperature stability of the peak tunneling current density of connecting tunneling diodes, which are necessary for the creation on their basis of multijunction photoconverters of powerful optical radiation, have been carried out. The structures of n++-GaAs/i-GaAs/i-AlGaAs/p++-AlGaAs of connecting TD with an intermediate undoped layer thickness of 7.5 nm and a growth temperature of 500 °C (structure ”A”) and with a thickness of 10 nm and a temperature of 450 °C (structure ”B”) were investigated. When heated to 80 °C, an increase in the peak tunneling current density of the TD structure ”B” by 4% is observed. However, for structure ”A”, a decrease in the peak tunneling current density by 5% with heating is observed. The factors leading to the appearance of a negative or positive temperature coefficient of the peak tunneling current density are determined using mathematical modeling of tunneling diodes based on GaAs/AlGaAs materials. By reducing the epitaxial growth temperature of n++–GaAs/i-GaAs/i-AlGaAs/p++–AlGaAs tunnel diode structure to 450 °C and including an undoped i-layer 10 nm thick between the degenerate layers ensure the temperature stability of peak current density when heated to 80 °C.