Mott-Schottky junction mediated photothermal-pyroelectric synergy for effective collection of waste heat in flexible sensing platform

Abstract

Solar–energy–induced photothermal–pyroelectric synergy sensing platform provides a win-win route to harvest waste heat and convert energy. However, the increase of carrier collision probability from high temperature inevitably leads to the loss of quantum efficiency. Herein, a flexible photothermal-pyroelectric electrode platform with Schottky junction was successfully constructed for maximum utilization of carrier. Under solar-simulated irradiation, the electron-rich and electron-depletion region formed by the Bi13S18Br2-S/alloy rectifier interface in flexible polyvinylidene difluoride-hexafluoropropylene film can increase the accumulation of photogenerated electrons. Meanwhile, the surface bound charges released by dipole oscillation in photothermal-pyroelectric field are continuously supplemented by the emerged high concentration of photogenerated electrons from the Schottky junction, and this synergistic effect prolonged their lifetimes and significantly improves the photoelectric conversion efficiency. To reasonably realize the accurate quantification of the simulated target, the cleavage activity of the CRISPR–Cas system can be specifically restored with the assistance of a synergistic dual-activator, releasing silica as a padlock to produce a target concentration-dependent photoelectric signal. Besides, the temperature variation on the electrode interface was simulated, revealing the synergistic effect between Schottky junction and photothermal–pyroelectric field under photoexcitation. This work broadens a new perspective for upgrading photoelectron utilization and overall performance of flexible sensing platform.