Fig. 2: Role of temperature for different coatings and salinity levels.

a The time trace of the measured open circuit voltage at ambient temperature is presented when the silicon surface temperature is increased and then allowed to cool down. The inset illustrates a qualitative rise in the chemical potential difference \((\varDelta \varPhi )\) for a single NP that has been wetted with electrolyte. b The time trace of the silicon surface temperature when the heater is turned on and turned off once the maximum is reached. The right axis shows the corresponding temperature difference between the bottom silicon surface and the top electrode (at the end of the liquid meniscus). c The voltage-temperature profile of the two devices was measured using the same top electrode at varying salinities. Each device consists of an identical silicon core and a dielectric shell made of Al₂O₃ and TiO₂: 1 mM (solid lines) and 100 mM (dashed lines). d (Top)Schematic representation of the core-shell nanopillars with Al₂O₃ (pink) and TiO₂ (purple) shells. (bottom) The slope of the V_OC-temperature curves for the linear regime (up to a 20 K increase in temperature) and the corresponding estimated values of enthalpy Δ_H.