Study of the Conduction Mechanism in Si-Based Light-Initiated Multi-Gate Semiconductor Switches

In this paper, software is used to simulate the conduction characteristics of silicon-based light-initiated multi-gate semiconductor switches. The switching processes of silicon-based light-initiated single-gate semiconductor switches and multi-gate semiconductor switches are compared. The transient state distribution characteristics of carriers during the switching process are analyzed, and the transport mechanism of carriers in the switches is investigated. The electron–hole pairs generated by a laser in the P-base region undergo both transverse diffusion and longitudinal transmission. The light-initiated multi-gate semiconductor switches exhibit shorter carrier transverse diffusion times and larger opening areas, resulting in increased maximum current and the current response speed after switch conduction. Moreover, we analyze the influence of different laser energies and distributions modes on the light-initiated multi-gate semiconductor switch. Lower laser energy activates the J1 junction but cannot trigger the J3 junction of the switch. Consequently, the carrier concentration remains low, and the switch does not fully open. Compared with a 980 nm laser diode (with a pulse width of 200 ns), a 980 nm Gaussian laser (with a half-peak width of 10 ns) enables faster switch activation.