Titanyl phthalocyanine gas sensor for NO 2 detection

Abstract

Titanyl phthalocyanine film prepared under room temperature and slow deposition rate comprises of α and amorphous phases, as proved by X-ray studies. After 3 h heat treatment at 250°C, α-phase was transformed into β-phase. TiOPc film gas sensor possesses satisfactory reproducibility and sensitivity toward NO 2 gas sensing. It exhibits a rather slow response, however, the recovery time is relatively short. After heat treatment, α-TiOPc film can be transformed into β-phase with a corresponding change in the response characteristics toward NO 2 sensing, i.e. an increase in the recovery time, and a decrease in the response time. The operating temperature at which the steady-state sensor current is maximized, T max, also increases.