On-Chip Growth of SnO2/ZnO Core–Shell Nanosheet Arrays for Ethanol Detection

In this letter, well-defined SnO2/ZnO core-shell nanosheet arrays (NSAs) are grown with an on-chip two-step process as gas sensing materials. A homogeneous precipitation method has been used to synthesize SnO2NSAs, following by atomic layer deposition of ZnO. The SnO2/ZnO core-shell NSAs based sensor exhibits significantly enhanced ethanol sensing response (13.3 at 100 ppm) and selectivity at 350 °C, as compared with the pure SnO2NSAs (2.7 at 100 ppm). The improvement of sensor performance can be ascribed to the SnO2/ZnO heterostructures formed in the core-shell NSAs, which suggests the promising application for MEMS compatible ethanol sensors.