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

Abstract

In this letter, well-defined SnO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /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 SnO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> NSAs, following by atomic layer deposition of ZnO. The SnO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /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 SnO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> NSAs (2.7 at 100 ppm). The improvement of sensor performance can be ascribed to the SnO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /ZnO heterostructures formed in the core-shell NSAs, which suggests the promising application for MEMS compatible ethanol sensors.