Intersubband emission from semiconductor superlattices excited by sequential resonant tunneling

Abstract

We present the first observation of infrared light emission from a semiconductor superlattice in a resonant-tunneling experiment. Radiation from the three lowest intersubband transitions is observed, proving resonant tunneling an effective means of populating high-lying states of the superlattice. The relative strength of the emission lines enables us to estimate the electron temperature below the optical-phonon energy to reach about 140 K, whereas transitions originating above the optical-phonon energy are strongly quenched.