High-Speed Photovoltaic Response of P-Type 6H-SiC

Abstract

The optoelectronic properties of 6-H silicon carbide (6H-Sic) were investigated using a lateral photoconductive switch. This material displayed a high-speed photovoltaic response to picosecond laser excitations: measurement-limited subnanosecond photovoltaic response times were observed for laser photon energies less than the 6H-Sic band gap energy. The photovoltaic response. as a function of laser wavelength and beam spatial position within the switching gap, was measured, along with the photo-catrier lifetime and optical absorption coefficient. The data show that the measured photovoltage is a sensitive function of both spatial position and optical absorption depth. Hypothetical arguments are presented that qualitatively explain the observed photovoltaic effects.