Structural disorder induced enhanced gas-sensing performance of ZnO with surface amorphous layer

The development of highly sensitive gas sensors is of great significance to the environment and human health. In this work, we demonstrate the enhancement of the gas-sensing performance of ZnO via employing disorder surface. The random arrangement of surface atoms could give rise to a coarse surface for improving gas adsorption. Moreover, due to the absence of carrier diffusion in amorphous layer, the Anderson localization could restrict the carrier interaction. Most crucially, the electron localization led by lattice disorder significantly elevate the gas monitoring sensitivity. As a result, the acetone sensitivity of ZnO is greatly enhanced (up to ∼ 20.8 times compared with the pristine sample). This work theoretically and experimentally investigate the role of surface disorder in enhancing gas-sensing performance, and also present a mild, low-cost method to modify the material for further applications.