Electrical and optical studies on metal-free phthalocyanine thin films

Phthalocyanines (Pcs) have attracted much attention because of their interesting electrical and optical properties. The potential applications of Pcs include gas sensors, rectifying devices, catalysts, and dyes. Here, the electrical and optical properties are reported for metal-free phthalocyanine thin films deposited at different substrate temperatures. It is found that the activation energy for conduction for H2Pc thin films decreases as the thickness of the film and substrate temperature are increased. The optical band gap is only slightly affected by varying the substrate temperature, but for the film deposited at a substrate temperature of 473 K, the bandgap shows a marked decreases. (CSA)