An electronic energy model for multi-stacking faults in reducing carrier lifetime in 4H-SiC epitaxial layers

•The minority carrier lifetime of different stacking faults in n-type 4H-SiC is studied.•A “step-structure” quantum well model for multi-stacking faults was proposed, taking into account the band bending by electron trapping in the stacking faults and electronic transitions between defect energy levels.•The carrier recombination at the SFs is discussed in terms of the accommodation ability of electrons inside the quantum wells. The effect of stacking faults (SFs) on carrier lifetime in 110 μm 4H-SiC epilayers has been studied using photoluminescence and microwave photoconductance decay. The carrier lifetimes are associated with different types of SFs. The SFs are distinguished as multi-SFs and mono-SFs in terms of their characteristic luminescence peaks. The average lifetime at multi-SFs is about 60 % of that at mono-SFs. Contrary to the quantum well models reported previously, multi-SFs decrease the minority carrier lifetime than mono-stacking faults even with shallower energy levels. A “step-structure” quantum well model is proposed to discuss the carrier dynamics for the enhanced recombination at the multi-stacking faults.