Breakdown behavior of SiC photoconductive switch with transparent electrode

Abstract

The breakdown behavior of a V-doped 4H silicon carbide photoconductive switch with a transparent electrode under a high electric field is studied. The device is triggered by a laser pulse below the bandgap wavelength with a repetition rate of 100 Hz. The light peak-power of the laser pulse reaches hundreds of kW, and the bias voltage is increased from 10 to 20 kV. With the accumulation of the number of pulses, the device shows breakdown behavior. Through the microscopic diagnosis of damaged and breakdown devices, according to the analysis of theoretical and simulation results, the breakdown of the device is due to the interaction between the laser and the aluminum doped zinc oxide transparent electrode on the device surface, resulting in the melting of the transparent electrode. The direct illuminate of the laser can form a field enhancement effect at the junction of the substrate and the transparent electrode, resulting in the damage of the device and the formation of pre-breakdown. Finally, the breakdown of the device inevitably occurs.

Recent progress of parameter-adjustable high-power photonic microwave generation based on wide-bandgap photoconductive semiconductors

“…The damage will first occur at this three-junction point, and then a pre-breakdown channel will be formed, finally leading to device breakdown failure. Figure 10(b) shows the optimized electrode structure, which uses a configuration with double-sided AZO transparent electrodes to homogenize the light spot, reduce the field strength, and increase the optical path [67] . As shown in Fig.…”