Three-dimensional Synergistic Strategy for Enhancing Voltage Output of ZnO Hydrovoltaic Devices

Abstract

Harvesting energy from low-frequency disordered raindrop motion has emerged as a promising hydrovoltaic technology for power generation in recent years. Hydrovoltaic devices have garnered widespread attention due to their miniaturization, portability, and substantial power generation potential. However, solid-liquid interactions in conventional hydrovoltaic devices are limited by the strong screening charge effect of the film structures, which leads to diminished device performance. This work presents a three-dimensional (3D) synergistic strategy for patterning zinc oxide (ZnO) hydrovoltaic devices to achieve high voltage output. At 50% relative humidity and 20 °C, the single patterned ZnO hydrovoltaic device can continuously generate a pulse voltage exceeding 9 V within 7 h, which is 15 times greater than the 0.6 V of similarly sized ZnO thin-film device. Further assembling multiple parallel units of patterned ZnO, a power supply is conducted well for a watch demonstration. Moreover, the lightweight (20 g m⁻²) and flexible characteristics of the patterned ZnO hydrovoltaic devices make them ideal for large-area integration and energy collection in practical applications. Thousands of printed and fabricated patterned ZnO devices will be expected to establish surface micro/nanostructure platforms for various energy devices in outdoor environments through extensive series-parallel connections.