We explore the nature of the electroluminescence (EL) emission of purely n-doped GaAs/AlGaAs resonant tunneling diodes (RTDs) and the EL evolution with voltage. A singular feature of such a device is unveiled when the electrical output current changes from higher to lower values and the EL on-off ratio is enhanced by two orders of magnitude compared to the current on-off ratio. By combining the EL and the current properties, we are able to identify two independent impact ionization channels associated with the coherent resonant tunneling current and the incoherent valley current. We also perform the same investigation with an associated series resistance, which induces a bistable electrical output in the system. By simulating a resistance variation for the current voltage and the EL, we are able to tune the EL on-off ratio by up to six orders of magnitude. We further observe that the EL on and off states can be either direct or inverted compared to the tunneling current of the on and off states. This electroluminescence, combined with the unique RTD properties, such as the negative differential resistance and high-frequency operation, enables the development of high-speed functional optoelectronic devices and optical switches.

We have studied the optical and electronic transport properties of n-type AlSb/GaInAsSb double barrier quantum well resonant tunneling diodes (RTDs). The RTDs were grown by molecular beam epitaxy on GaSb substrates. Collector, quantum well, and emitter regions are comprised of the lattice-matched quaternary semiconductor Ga0.64In0.36As0.33Sb0.67. Photoluminescence emission spectra reveal a direct bandgap semiconductor with a bandgap energy of Eg≈0.37 eV, which corresponds to a cut-off wavelength of λ≈3.3 μm. The composition-dependent bandgap energy is found to follow Shim’s model. At room temperature, we observe resonance current densities of jres=0.143 kA cm−2 with peak-to-valley current ratios of up to PVCR=6.2. At cryogenic temperatures T<50 K, the peak-to-valley current ratio increases up to PVCR=16.

We investigate the energy relaxation segmentation in a resonant tunneling heterostructure by assessing the optical and transport dynamics of nonequilibrium charge carriers. The electrical and optical properties are analyzed using electronic transport measurements combined with electro- and photoluminescence spectroscopies in continuous-wave mode. Our results suggest that hot electron and hole populations form independent nonequilibrium systems that do not thermalize among them and with the lattice. Consequently, the carrier effective temperature changes independently at different regions of the heterostructure, with a population distribution for holes colder than for electrons.

Resonant tunneling diode photodetectors appear to be promising architectures with a simple design for mid-infrared sensing operations at room temperature. We fabricated resonant tunneling devices with GaInAsSb absorbers that allow operation in the 2–4 μm range with significant electrical responsivity of 0.97 A/W at 2004 nm to optical readout. This paper characterizes the photosensor response contrasting different operational regimes and offering a comprehensive theoretical analysis of the main physical ingredients that rule the sensor functionalities and affect its performance. We demonstrate how the drift, accumulation, and escape efficiencies of photogenerated carriers influence the electrostatic modulation of the sensor’s electrical response and how they allow controlling the device’s sensing abilities.