To realize an asymmetric function blockable sneak currents in the resistive switching memory device, we propose a novel schottky diode based high charge density resistive switching device based on zinc oxide (ZnO) and poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) heterojunction, which is structured with bottom and top electrode as indium tin oxide (ITO) and silver (Ag), respectively. The heterojunction layers are deposited through a spin coater on ITO coated polyethylene terephthalate (PET) substrate. The hetrojunction resistive switching device is measured over more than 500 endurance cycles on dual polarity voltage of ± 3 V. The stability of the memory device is analyzed for more than 30 days with high resistance state (HRS) and low resistance state (LRS) as 531047870.8 Ω and 1001636.011 Ω, respectively, at reading voltage of 1.28 V in forward current, and its Roff/Ron ratio is recorded as ~ 530. In reverse current, the HRS ~ 153081392.6 Ω and LRS ~ 19034020.25 Ω are recorded at voltage read of ~ − 1.28 V and they are both high resistance as its Roff/Ron ratio is ~ 8.04. This asymmetric function insures that the proposed memory device helps to reduce the sneak current. Hence, it can be applied in flexible resistive switching devices to blocking sneak current problem.