Studies of surface resistance of copper(II) phthalocyanine thin films by using a near-field scanning microwave microscope

Abstract

We observed the surface resistance of copper(II) phthalocyanine (Cu–Pc) thin films dependence on substrate heating temperature by using a near-field scanning microwave microscope (NSMM). The NSMM system was coupled to a dielectric resonator with a distance regulation system at an operating frequency f=4.5–5.5 GHz. The crystal structures and surface resistance of Cu–Pc thin films due to different heating temperatures were observed by using X-ray diffraction including the 2 θ and φ-scan and the near-field scanning microwave microscope. As the temperatures increased from room temperature to 200 °C, the crystal structure of Cu–Pc thin films was transformed from monoclinic α-Phase to thermally stable monoclinic β-Phase. The changes in surface resistance of Cu–Pc thin films due to different substrate heating temperatures were investigated by NSMM by measuring the reflection coefficient S 11. The surface resistance of Cu–Pc thin films depends on the morphology and crystal alignment of these films. When the substrate temperature for deposition was 150 °C, the minimum surface resistance of Cu–Pc thin films was obtained.