Enhanced Durability of High-Power Avalanche GaAs Photoconductive Semiconductor Switch Utilizing Advanced Double-Sided Cooling Configuration

The formation of ultrahigh density current filaments within avalanche gallium arsenide photoconductive semiconductor switches (GaAs PCSSs) significantly reduces their operational lifetime and limits their applicability in real-world engineering applications. To significantly enhance the durability of high-power avalanche GaAs PCSS, a high voltage-resistant double-sided cooling device is explored in this article. At 40 kV dc bias and 2 Hz operation, the avalanche GaAs PCSS with double-sided heat dissipation design exhibits a lifetime of up to 7.91× 10⁴ times. Compared to the devices with no heat dissipation and single-side heat dissipation, the double-side-structured GaAs PCSS demonstrates a lifetime improvement of over two times and one time, respectively. The double-sided heat dissipation structure improves the lifetime because it distributes the local heat more evenly. This prevents transient temperature rise at localized locations and mitigates the heat accumulation effect near the electrodes. The output characteristics of the devices are analyzed at 30-60 kV dc bias. An output waveform with a pulse rise time of less than 1 ns, a pulsewidth of about 4.7 ns, and a load output power of about 17 MW is obtained at 60 kV. The jitter characteristics of the device are evaluated, and it is found to have a jitter time of about 48 ps for 354 operations.