Phase transition of copper (II) phthalocyanine thin films characterized by a near-field scanning microwave microscope

To study the phase transition of copper (II) phthalocyanine (Cu-Pc) thin films, we measured the surface resistance using a near-field scanning microwave microscope (NSMM) by measuring the microwave reflection coefficient S11. The crystal structure of Cu-Pc thin films transformed from the α-phase of the orthorhombic crystal to the thermally stable β-phase of the monoclinic crystal as the substrate heating temperatures increased. The surface resistance depended on the crystal structures of the Cu-Pc thin films. As the phase changed from the α-phase to the β-phase, the surface resistance of the Cu-Pc thin films decreased.