STRUCTURE OF (ALPCF)N THIN-FILMS AS A FUNCTION OF ANNEALING CONDITIONS

Some years ago we showed that polyfluoro-aluminum phthalocyanine ((AlP cF)n) thin films can be used as sensitive elements in NO2 gas sensors provided that they are heated at 150-200-degrees-C in order to respond reversibly and rapidly to the presence of gas. It is therefore import ant for the films to be stable in this temperature range. The aim of t he present study is to investigate by XRD and SEM the evolution of the crystallinity and surface aspect of (AlPcF)n films deposited on glass or alumina substrates then annealed in various conditions of temperat ure, atmosphere and duration. The results show that room-temperature d eposited films are poorly crystalline and that their crystallinity rem ains low even after annealing, which ensures good structural stability of the films for gas-sensor applications.