Analysis of GaN cap layer effecting on critical voltage for electrical degradation of AlGaN/GaN HEMTShenqi Qu, Xiaoliang Wang, Hongling Xiao, Cuimei Wang, Lijuan Jiang, Chun Feng, Hong Chen, Haibo Yin, Junda Yan, Enchao Peng, He Kang, Zhanguo Wang and Xun HouEur. Phys. J. Appl. Phys., 68 1 (2014) 10105DOI: https://doi.org/10.1051/epjap/2014140019