Color Centers Enabled by Direct Femto-Second Laser Writing in Wide Bandgap Semiconductors

• Main Authors: Stefania Castelletto, Jovan Maksimovic, Tomas Katkus, Takeshi Ohshima, Brett C. Johnson, Saulius Juodkazis
• Format: Article
• Language: English
• Published: MDPI AG 2021-12-01
• Series: Nanomaterials
• Subjects: femtosecond laser writing; color centers; vacancies; silicon carbide; gallium nitride; spectroscopy
• Online Access: https://www.mdpi.com/2079-4991/11/1/72

Color centers in silicon carbide are relevant for applications in quantum technologies as they can produce single photon sources or can be used as spin qubits and in quantum sensing applications. Here, we have applied femtosecond laser writing in silicon carbide and gallium nitride to generate vacancy-related color centers, giving rise to photoluminescence from the visible to the infrared. Using a 515 nm wavelength 230 fs pulsed laser, we produce large arrays of silicon vacancy defects in silicon carbide with a high localization within the confocal diffraction limit of 500 nm and with minimal material damage. The number of color centers formed exhibited power-law scaling with the laser fabrication energy indicating that the color centers are created by photoinduced ionization. This work highlights the simplicity and flexibility of laser fabrication of color center arrays in relevant materials for quantum applications.