Electrical parameters and gas sensing behaviour of ClInPc thin film devices

The electrical characteristics of thermally evaporated Chloroindium phthalocyanine thin films (ClInPc) are studied. A number of parameters are evaluated on the basis of the theory of space-charge-limited conduction. ClInPc thin films are extremely stable, in terms of both resistance to chemical attack and thermally, no hysteretic was observed after temperature cycling between room temperature and 500 K. DC current-voltage and current-temperature characteristics were obtained for ClInPc in vacuum and on exposure to dry air (20% O-2) in both the dark and under illumination with visible light. The conductivity data were analysed in the framework of band theory to elucidate information about the activation energy E-ac,forbidden band gap (E-c-E-v), domain or acceptor energy levels (E-e, E-h). In the present work we also examine the response of ClInPc to O-2 and NO2 at different temperatures.