Electrical properties of defects in 4H-SiC investigated by photo-induced-currents measurements

In this paper we have studied the connection between crystal quality and electrical transport in 4H-SiC by simultaneous micro-photoluminescence (?PL) and photocurrent (PC) measurements. We have used a focused HeCd laser at 325 nm (i.e. above bandgap) to measure with a spatial resolution of few microns both the ?PL spectra and the I-V characteristics in 4H-SiC/Ni Schottky diodes. We found that the PC signal acquired along a defect can give information on its spatial distribution in depth. The minority carrier lifetime has been also estimated and its dependence on the emission wavelength has been determined for several stacking faults.