Enhancing the gas-sensing properties of (RuPc)(2) thin films by thermally induced morphological stabilizing effects

We report on the use of thermal annealing to improve the behavior of NO2 gas-sensing ruthenium phthalocyanine films at high temperatures. The approach used, based on the study of the effect of temperature on the film morphology, makes use of in situ energy dispersive X-ray reflectometry and atomic force microscopy. The results show that the morphological changes, induced by high working temperatures, strongly affect the material sensing ability. Furthermore, we demonstrate that the film morphology may be stabilized by thermal annealing treatments, thus enhancing the sensor performances in terms of response times and the capability to work at high temperatures.