The synthesis of ZnO films by optimized electrodeposition led to the achievement of a critical electric field of 800 kV/cm. This value, which is 2−3 times higher than in monocrystalline silicon, was derived from a vertical Schottky diode application of columnar-structured ZnO films electrodeposited on platinum. The device exhibited a free carrier concentration of 2.5 × 10 15 cm −3 , a rectification ratio of 3 × 10 8 , and an ideality factor of 1.10, a value uncommonly obtained in solution-processed ZnO. High breakdown strength and high thickness capability make this environment-friendly process a serious option for power electronics and energy harvesting.