The Effect of Substrate Temperature on Structure and Optical Properties of Copper (II) Phthalocyanine (CuPc) Thin Films Prepared by Organic Evaporation

Abstract

The influence of substrate temperature controls on copper (II) phthalocyanine (CuPc) organic thin films onto glass substrate by organic evaporation system has been examined by X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM) and UV-VIS spectrophotometer. The two control methods are an on-off switching temperature control and a phase temperature control. The various substrate temperatures were controlled at 27, 80, 100, 120 and 150 degC, respectively. The thickness of all thin films is 30 nm. The XRD results from both methods show strongly peaks in orientation of [200] plane as alpha-phase monoclinic structure. By an on-off switching controlled temperature, the intensity of XRD peaks is increased with increasing substrate temperature. While intensity of XRD results from a phase controlled temperature shows increasing from 27 to 100 degC but decreasing from 120 to 150 degC. The CuPc grown at 150 degC exhibits nanorod-like structure obtained from an on-off switching temperature control and fiber-like structures obtained from a phase temperature controls. The optical absorptions of CuPc thin films of both methods determined from UV-VIS spectrophotometer show two strong peaks at 330 nm and 620 nm, denoted the B-band and Q-band, respectively.