Tailoring all-inorganic cesium lead halide perovskites for robust triboelectric nanogenerators

Triboelectric nanogenerators (TENGs) have attracted considerable interests because of their high conversion efficiency from low-frequent mechanical energy to electricity. Robust dielectric materials are critical in enhancing the contact electrification charge density of TENGs. Herein, all-inorganic cesium lead halide (CsPbX3, X = I, Br, Cl) perovskites with tunable morphologies and dielectric properties are synthesized through a facile solvent etching method and applied as the triboelectric materials in perovskite TENGs. The influences of effective contact area and the dielectric properties associated with electron donating capacity of perovskite films are systematically investigated through solvent and compositional engineering. Compared with the all-inorganic perovskite free of etching, the crystal growth conditions are well controlled. In addition, the doping of Cl- or I- ions is in favor of regulating the polarity and electronic structure of the [PbBr6](4-) octahedral. Benefitting from the physical surface engineering approaches for enhancing the triboelectric charge density and the chemical doping for regulating dielectric property, an open-circuit voltage of 192 V, a short-circuit current of 16.7 mu A and maximum power density of 1.2 W m(-2) at a contact frequency of 0.5 Hz are achieved in the champion CsPbBr2.6I0.4 TENG. The discovery of extraordinary dielectric behavior of the perovskite halides may pave the way of perovskite TENGs with boosting triboelectric charge density for mechanical energy harvesting.