Numerical simulation of diode and thyristor-like structures for power and optoelectronic applications.

摘要

We have applied a commercial TCAD package for numerical simulations of novel semiconductor devices for power and optoelectronic applications.; We have introduced a novel concept of vertically stacked power PIN-diode and thyristor structures interconnected in series with tunnel junctions. We have shown both analytically and numerically that the concept allows a drastical decrease in the forward voltage drop across the device and, therefore, thermal losses, while the breakdown voltage remains the same or becomes even greater. We have also simulated stacked power thyristors and prove the applicability of the concept to them. Non-stationary simulations have shown that the stacked PIN diodes are free of unwelcome hot-electron effects and possess higher speed of operation.; The application of our concept to the design of microwave PIN switches has been shown to be advantageous at high microwave frequencies. We have performed an analysis of the performance of light-emitting diodes and shown that there is a possibility to increase their speed of operation considerably by controlling the voltage across the device rather than the current flowing through it. The application of this method results in a large pulsed current that rapidly removes excessive carriers from the active region if the device is being switched off and injects them into the active region if the device is being switched on. Our numerical simulations have shown the characteristic time of these processes to be approximately two orders of magnitude smaller than the recombination time.; We have applied the concept of voltage-control switching to light-emitting thyristor-like structures operating in the regime of incomplete gate turn-off (IGTO). The simulations have shown that the homogeneous IGTO-state in a narrow heterostructure AlGaAs/GaAs TLS can be established very fast if it is controlled by the voltage on two gate contacts attached to its bases. The characteristic time of this process is about 10--11 s, which corresponds to the voltage-control switching times in light-emitting diodes and is two orders of magnitude smaller the characteristic time of one-gate switching.; We have also simulated the inhomogeneous IGTO-state in a sufficiently wide heterostructure AlGaAs/GaAs TLS in which a GaAs light-emitting region is placed between AlGaAs bases. Such a design allows one to reach a considerable increase in light emission from the device's center and to diminish the length of both bases as well as to increase the quantum efficiency. The major result of these simulations is that the use of two gates allows a more effective and fast control of the inhomogeneous IGTO-state.