S-shaped current-voltage characteristics and bistability in the laser generation spectrum of multiple-barrier p-i-n resonant tunneling devices

A p-i-n resonant tunneling device displaying current bistability accompanied by bistability in the spectra of electroluminescence (EL) and laser generation is designed and demonstrated. The device is based on an Al_0.4Ga_0.6As/GaAs graded index waveguide heterostructure with the multiple-barrier active region designed to obtain simultaneous resonant injection of electrons and heavy holes. The study of bias-dependent EL and photoluminescence confirms a resonant occupation of the excited subbands. The observed S-shaped current-voltage characteristic originates most probably from bipolar charge redistribution in the intrinsic region.