Fabrication and photoluminescence of SiC quantum dots stemming from 3C, 6H, and 4H polytypes of bulk SiC

We report the fabrication and photoluminescence properties of the colloidal SiC quantum dots (QDs) stemming, respectively, from diminishing different polytypes (3C, 6H, and 4H) of bulk SiC crystals using electrochemical method. The three types of obtained SiC QDs show unexpected quite-similar photoluminescence, photoluminescence excitation, and transient photoluminescence properties. This strange phenomenon is explained by using the polytypic transformations of the colloidal SiC QDs driven by ultrasonic waves. Our results will greatly deepen our understanding of the fundamental physics of nanoscale SiC.