Optical switching of defect charge states in 4H-SiC

Abstract

We demonstrate optically induced switching between bright and dark charged divacancy defects in 4H-SiC. Photoluminescence excitation and time-resolved photoluminescence measurements reveal the excitation conditions for such charge conversion. For an energy below ~1.3 eV (above ~950 nm), the PL is suppressed by more than two orders of magnitude. The PL is recovered in the presence of a higher energy repump laser with a time-averaged intensity less than 0.1% that of the excitation field. Under a repump of 2.33 eV (532 nm), the PL increases rapidly, with a time constant ~30 $\mu$s. By contrast, when the repump is switched off, the PL decreases first within ~100-200 $\mu$s, followed by a much slower decay of a few seconds. We attribute these effects to the conversion between two different charge states. Under an excitation at energy levels below 1.3 eV, V${}_{Si}$V${}_C$${}^0$ are converted into a dark charge state. A repump laser with an energy above 1.3 eV can excite this charged state and recover the bright neutral state. This optically induced charge switching can lead to charge-state fluctuations but can be exploited for long-term data storage or nuclear-spin-based quantum memory.

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References in corpus (5)

• Coherent control of single spins in silicon carbide at room temperature
• Isolated electron spins in silicon carbide with millisecond-coherence times
• Low Temperature Studies of Charge Dynamics of Nitrogen-Vacancy Defect in Diamond
• Optical charge state control of spin defects in 4H-SiC
• Long-term data storage in diamond

Cited by in corpus (7)

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• Site-dependent properties of quantum emitters in nanostructured silicon carbide
• Stimulated Emission Depletion Microscopy with Color Centers in Hexagonal Boron Nitride
• Photoelectrical detection and characterization of divacancy and PL5-PL7 spins in silicon carbide