Effects of localized laser-induced heating in the photoluminescence of silicon-vacancy color centers in 4H-SiC

TL;DR

This study investigates how localized laser heating affects the photoluminescence of silicon vacancy centers in 4H-SiC, revealing temperature-dependent spectral shifts and broadening, and proposing their use as local temperature sensors.

Contribution

It demonstrates the impact of laser-induced heating on PL spectra of V_Si centers and models local temperature effects, advancing understanding of optical properties in 4H-SiC.

Findings

Laser heating causes ZPL peak decrease, redshift, and broadening.

ZPL energy shifts can determine local temperature via Varshni equation.

Color centers' ZPLs can serve as local temperature probes.

Abstract

Silicon vacancy ($\mathrm{V_{Si}}$) color centers in 4H-SiC are optically accessible through their zero-phonon line (ZPL) photoluminescence (PL), which is sensitive to the sample temperature. We report the effects of localized laser-induced heating in 4H-SiC by measuring the PL spectra of $\mathrm{V_{Si}}$ color centers. The effects of laser-induced heating manifest as the decrease in the peak height, redshift, and broadening of the ZPLs in the PL spectrum. The local temperature in the sample can be determined from the center energy of the ZPLs by using the Varshni equation. The sample temperature can be modeled as a system in contact with a thermal reservoir while being heated by a laser beam. This work highlights the importance of considering laser-induced heating in the optical properties of color centers in 4H-SiC and their potential applications. The result also suggests that the sharp and bright ZPLs of color centers can be used as local temperature probes in 4H-SiC devices.