Study the Effect of Annealing Temperature on the Structural, Morphology and Electrical Properties CoPc Thin Films

Abstract

Cobalt Phthalocyanine (CoPc) thin films with different annealing temperatures (298,358,408,458)K have been prepared by thermal evaporation technique on glass substrate at RT under vacuum of 10-5 mbar Using Edwards 306 system with rate of deposition equal to 15 nm/minute. The structure and surface morphology of CoPc as powder and thin film of thickness (150 nm) were studied using X-ray diffraction and atomic force microscope (AFM), and showed that there are changes and enhance in the crystallinity and surface morphology due to change in the annealing temperatures. Analysis of X-rays diffraction patterns of CoPc in powder form showed that it had an β-polycrystalline phase with monoclinic system. Thermal evaporation of CoPc at different annealing temperatures led to α-crystalline films oriented preferentially to the (100) plane with different annealing temperatures. The mean crystallite size increased with annealing temperatures. This result was supported by AFM measurements, which exhibited a relatively larger grain size. The electrical properties of these films were studied with different annealing temperature, CoPc has two activations energy. Carrier's concentration and mobility was calculated. Hall measurements showed that all the films are p-type.