A novel III–V semiconductor material for NO2 detection and monitoring

This paper deals with the chemical and sensing properties of n-type indium phosphide (InP) epitaxial layers, which were applied in a novel resistive structure for gas detection. The influence of working temperature on the structure response to the oxidising gas, nitrogen dioxide (NO2), in the ppb range was investigated. Also, the in-depth profiles of charge carrier concentration and resistivity of the InP material were calculated at various temperatures. In order to understand better the sensing mechanism, a detailed analysis of the chemical properties of the InP surface before and after gas action was performed by means of X-ray photoelectron spectroscopy (XPS) combined with Auger spectroscopy (AES) and Ar+ sputtering of the sample.