Long-lived SiV⁻ center induced by nanosecond high-voltage pulse discharge

Defect and impurity centers in diamond can exist in multiple charge states. A notable example is the negatively and neutrally charged nitrogen-vacancy center in diamond, whose optical and spin properties are very different. Recent DFT studies show that an energetically favorable charge state can be controlled by adjusting the chemical potential of the diamond sample, which often requires significant materials engineering. This study presents an alternative approach for the control of charge states with the use of nanosecond high-voltage pulse discharges. We demonstrate the control of silicon-vacancy (SiV) centers in diamond. Using time-resolved photoluminescence (PL) spectroscopy measurement of the SiV centers with the application of nanosecond high-voltage pulses, we show the emergence of the negatively charged SiV⁻ state. We also employ the time-resolved PL measurements and show that the population of the induced SiV⁻ charge state decays exponentially, and the lifetime of the charge state is determined to be in the range of 200 - 1100 ms. The observed long-lived charge state is potentially useful for applications based on the SiV^-center. This method also paved the way to access various charge states of defect and impurity centers in diamond and wide-bandgap semiconductors.