Three-terminal mid-IR tunable emitters based on Wannier–Stark ladder transitions in semiconductor superlattices

Abstract

We report the generation of widely tunable mid-infrared (5–13 µm) electroluminescence in a heterostructure bipolar transistor-like device. The radiation is associated with transitions between Wannier–Stark ladder states of a periodic superlattice included in the intrinsic region between base and collector. At low fields the spectrum is dominated by diagonal 1–1 transitions between ground levels localized in neighbouring wells. At larger fields, merging with the 2–1 intersubband emission is observed until intervalley Γ–X electronic scattering limits the radiative efficiency above 230 kV cm−1.