Large Vertical Piezo-Optoelectronic Effect in SiC/Si Heterostructure

This paper reports, for the first time, the effect of mechanical stress or strain on the vertical photovoltage effect, which is named as the piezo-optoelectronic effect, in a SiC/Si heterostructure. The vertical photovoltage across the heterostructure changes significantly according to the exerted strain under light illumination. The change is about hundred-fold that of lateral photovoltage under strain application in the literature. The phenomenon is explained by the alteration in the out-of-plane effective mass, energy level, and repopulation of light and heavy holes under the applied strain. This study offers a novel method to develop ultrasensitive self-powered mechanical sensors.