Characterization of Trapping Effects Related to Carbon Doping Level in AlGaN Back-Barriers for AlGaN/GaN HEMTs - Ferrand-Drake Del Castillo, Ragnar; Chen, Ding-Yuan; Chen, J. T.; Thorsell, Mattias; Darakchieva, Vanya; Rorsman, Niklas (IEEE Transactions on Electron Devices, 2024)