A novel method for predicting optimal gas sensing temperature of morphologically distinct nanostructured Schottky interfaces

Nanostructured metal-oxide Schottky interfaces enable substantially enhanced gas response for gas sensors. Although it is widely known that operating these gas sensors requires heating to an elevated temperature for optimal gas response, the fundamental principles that governs this temperature-dependent gas response has yet been well understood. In this work, we propose a novel technique based on thermionic field emission (TFE) theory for predicting the optimal gas sensing temperature of morphologically different nanostructured metal-semiconductor (Schottky) interfaces. Through the fabrication and characterization of Pt/MoO3 Schottky contacted sensor devices, we found the previously unreported correlation between TFE transport and optimal gas sensing temperature. By establishing the proposed technique on the connection between temperature-dependent gas response and electron transport, prediction of optimal sensing temperature can be performed via simple I-V measurements, often to a high accuracy of several degrees. Experimental results indicate that the technique is applicable across a wide variety of morphologically distinct devices.