Numerical simulation of semiconductor light emitters based on the aluminum gallium indium nitride material system and based on novel multiterminal gallium arsenide thyristors.

摘要

This dissertation presents results of the investigation of novel light emitting semiconductor devices.; For the investigation of light emitters based on the AlGaInN material system, a new, highly convergent, and memory efficient algorithm for their numerical simulation has been developed.; The results obtained, from this program, explain the experimentally observed saturation of output power, and the saturation of spectral broadening, as the injected current is increased, in light emitting diodes, when band to impurity level recombination processes are dominant. Results for AlGaN based double heterojunction lasers and separate confinement heterostructure lasers, demonstrates threshold current density minimization by proper choice of the active region thickness and the waveguiding regions' aluminum composition. Also, the behavior of the threshold current density for different optical loss values of GaN are demonstrated.; Multiterminal GaAs based light emitters were investigated. Simulation results of ridge shaped gate-turn-off thyristors, operating in the incomplete turn off regime, demonstrate the applied currents and voltages necessary to squeeze the current flow path, and ways to improve the device's performance. This squeezing can increase the material gain, and induce lasing.; During the investigations of this thyristor, a new three terminal, spatially switching light emitting ridge shaped thyristor structure was discovered. Results demonstrate that the current flow channel will shift from one edge of the ridge structure, to the other, as the gate electrode's bias is changed. The operation of this device will be discussed.