Charge accumulation in the two-dimensional electron gas emitter of a resonant-tunneling diode

The spectral analysis of a two-dimensional accumulation layer of a resonant-tunneling light-emitting diode is reported and results in an accurate determination of the charging and discharging of a two-dimensional electron gas. Whereas the tunneling well of a traditional resonant-tunneling diode can attain a density into the ${10}^{11}$ ${\mathrm{cm}}^{\mathrm{-}2}$ regime for wide barriers, occupations of ${10}^{12}$ ${\mathrm{cm}}^{\mathrm{-}2}$ are meausured here in the two-dimensional emitter. A hot electron population is observed in the emitter and evidence for removal of this population by resonant tunneling into the tunneling quantum well is given. Together with the presence of strong hole confinement, the two-dimensional emitter generates intense near-infrared emission.