Enhancing electricity generation during water evaporation through a symmetric double Schottky-junction design.

Extensive efforts have been made to investigate energy conversion process based on metal-semiconductor Schottky junctions. In this study we report the exploration of electricity generation through water evaporation on the surface with double Schottky junctions of symmetric design. By using such symmetric Schottky junctions at both side of a silicon wafer, the electricity generation is enhanced over the system with just a single Schottky junction. In the symmetric-junction system, water evaporation on the surface of one Schottky junction breaks the symmetry, leading to the generation of a continuous and direct current. The evaporation-induced cooling and continuous liquid-solid contact electrification at the Schottky junction on one side of the system enable the fast flow of the hot electrons across the Schottky junction on the other side. This work not only demonstrates a continuous and direct-current generation system, which has the potential of harvesting a broad range of waste heat and enabling many promising applications, but also offers a general strategy using the symmetric design of Schottky junctions to enhance electricity generation in diverse energy conversion systems. [Display omitted] • Symmetric double Schottky junction based device shows enhanced electricity generation during water vaporization. • Cooling and contact electrification during the water vaporization process synergistically enable the enhanced electricity generantion. • The maximum continuous and direct-current density of ∼ 1 A m^–2 and peak power density of 13 mW m^–2 were achieved. [ABSTRACT FROM AUTHOR]