Development and study of the $p$–$i$–$n$-диодов GaAs/AlGaAs tunnel diodes for multijunction converters of high-power laser radiation

The creation of connecting tunnel diodes with a peak tunneling-current density higher than the density of the short-circuit current of photoactive $p$–$n$ junctions is an important task in the development of multijunction photoconverters (III–V) of high-power optical radiation. Basing on numerical simulation of the J–U characteristics of tunnel diodes, a method is proposed for increasing the peak tunneling-current density by including a thin undoped $i$-type layer with a thickness of several nanometers between degenerate layers of the tunnel diode. The $p$–$i$–$n$-GaAs/Al$_{0.2}$Ga$_{0.8}$As structures of the connecting tunnel diodes with a peak tunneling-current density of up to 200 A/cm$^2$ are grown by molecular-beam epitaxy.