“…However, most applications are focused on the static PN structure and there has little exploration on the dynamic PN junction both in information and energy fields (Matyba et al., 2009, Burgener et al., 2011). Recently, high current density direct-current generators have been discovered, which attracts intense attention (Hao et al., 2019, Lin et al., 2019, Lin et al, 2019, Liu et al., 2018a, Liu et al., 2018b, Liu et al., 2019, Shao et al., 2016, Shao et al., 2019a, Shao et al., 2019b). Specifically, we have proposed a physical picture based on the semiconductor physics rather than the triboelectric theory at the interface (Hao et al., 2019, Lin et al., 2019, Lin et al, 2019).…”