Reversible P–N transition sensing behavior obtained by applying GQDs/Pt decorated SnO2 thin films at room temperature

Abstract

In this work, a GQDs/Pt decorated nanoporous SnO₂ thin film with high crystallinity and nanostructure ordering is firstly fabricated in situ on a sensor device using water vapor hydrothermal treatment which then acted as an excellent acetone chemiresistor. Intriguingly, the nanoporous SnO₂ thin film displays a regular change of sensing behavior with reversible transition from p- to n-type sensing as a function of acetone concentration (AC) and GQD content (GC) at room temperature. An AC–GC transition diagram has been created in terms of the gas sensing response. Accordingly, this will be a promising way to finding a versatile sensor system, by the precise control of the GQDs content on the SnO₂ surface. The mechanism deriving from the acetone sensing transitions points out the nature of the materials.