Current Self-Oscillations in Negative Effective Mass TerahertzOscillators

We theoretically study current self-oscillations and spatiotemporal current patterns in quantum-well negative-effective mass (NEM) p⁺pp⁺ diodes by considering scattering contributions from impurity, acoustic phonon, and optic phonon. It is indicated that both the applied bias and the doping concentration strongly influence the patterns and self-oscillating frequencies. The NEM p⁺pp⁺ diode presented here may be used as an electrically tunable terahertz source.