fig3

Figure 3. Schematic diagram of a typical p-n heterojunction formed at the heterophasic interface of a p-type (BCFZY)-n-type (ZnO) semiconductor membrane and the corresponding energy band alignment mechanism proposed for interpreting the charge separation and ionic transportation process^[30]. BCFZY: BaCo_0.4Fe_0.4Zr_0.1Y_0.1O_3-δ; NCAL: Ni_0.8Co_0.15Al_0.05LiO_2-δ; CB: conduction band; VB: valence band.