ZnO/0.5BZT-0.5BCT heterostructures exhibited resistive switching (RS) ratio ≥ 10 4. Effect of oxygen pressure used in the deposition of ZnO on RS ratio is highlighted. Determination of the Band alignment in ZnO/0.5BZT-0.5BCT heterojunctions from XPS. Resistive Switching is explained based on charge coupling effect.