Monte Carlo study of multibarrier heterostructure switch

A multibarrier heterostructure GaAs/AlAs current switching diode has been investigated by Monte Carlo method. The switching phenomenon is based on electron tunnelling and thermoemission from the GaAs wells to the AlAs barriers, electron drift across the thin AlAs barriers followed by a subsequent impact ionisation in the undoped GaAs layers. The calculated switching voltage is close to 100 V for the diode involving four AlAs barriers at 300 K lattice temperature. The estimated switching time is in the order of 10 ps

Optical pump rectification emission: route to terahertz free-standing surface potential diagnostics

We introduce a method for diagnosing the electric surface potential of a semiconductor based on THz surface generation. In our scheme, that we name Optical Pump Rectification Emission, a THz field is generated directly on the surface via surface optical rectification of an ultrashort pulse after which the DC surface potential is screened with a second optical pump pulse. As the THz generation directly relates to the surface potential arising from the surface states, we can then observe the temporal dynamics of the static surface field induced by the screening effect of the photo-carriers. Such an approach is potentially insensitive to bulk carrier dynamics and does not require special illumination geometries

Efficiency of GaAs-Based Pulsed Terahertz Emitters

Terahertz emission from the electron-hole plasma excited by a femtosecond optical pulse in GaAs-based emitters is studied by the Monte Carlo simulations. The THz energy radiated from the n- and p-doped GaAs surface THz emitters, from the contactless p-i-n emitter, and from the photoconductive emitter is evaluated. The obtained results show that the THz energy radiated by the photoconductive emitter exceeds the energy radiated by the surface and p-i-n THz emitters by more than one order of magnitude

Efficient Terahertz Emission from InGaN/GaN Heterostructure

Terahertz emission from the freestanding InGaN/GaN heterostructure illuminated by femtosecond optical pulse is considered using Monte Carlo simulations. The results of Monte Carlo simulations show that the power of terahertz emission from InGaN/GaN heterostructure exceeds the power of the emission from InN surface by one order of magnitude

Vertical Electron Transport in GaN/AlGaN Heterostructures

Nonequilibrium dc and large-signal ac vertical electron transport in GaN/AlGaN heterostructures is investigated by Monte Carlo simulations. The symmetric two-barrier GaN/AlGaN heterostructures are studied. The results of simulations show that polarization charges have a profound effect on dc and large-signal ac characteristics of vertical electron transport in GaN/AlGaN heterostructures. Under certain composition, geometry and doping profile, the GaN/AlGaN heterostructures may become bipolar, i.e., the inversion layers may originate at heterointerfaces due to strong built-in electric fields, which are induced by polarization charges