In this paper we have studied the connection between crystal quality and electrical transport in 4H-SiC by simultaneous micro-photoluminescence (μPL) and micro-photocurrent (μPC) measurements. We have used a focused HeCd laser at 325nm (ie above bandgap) to measure with a spatial resolution of few microns both the μPL spectra and the IV characteristics in 4H-SiC/NiSi Schottky diodes. We found that extended defects exhibiting a photoluminescence peak located at 2.9 eV (ie single Shockley or bar shaped stacking faults) can produce an increase of the measured PC whereas other defects, such as the (4, 4) stacking fault, can be considered as ‘killer defects’, strongly reducing the photocurrent.