Study of Optical and Electrical Properties of Tin-Doped Magnesium Phthalocyanine Thin Films Grown by Thermal Co-Evaporation

The aim of this work is to investigate specific properties of tin-doped magnesium phthalocyanine (Sn-doped MgPc) thin films grown by thermal co-evaporation. Morphological, optical and chemical properties of the doped-films were characterized by atomic force microscopy (AFM), UV-Visible spectroscopy and X-ray photoelectron spectroscopy (XPS). Furthermore, electrical properties of ITO/Sn-doped-MgPc/Al devices such as carrier mobility and carrier concentration were extracted from current-voltage and capacitance-voltage measurements. Morphology of the doped films shows strong dependence on the existence of Sn in the doped films as clearly observed by changing of features of the film surface e.g. surface grain size and roughness. Optical absorption spectra of all conditions provide regular three dominant beta-phase peaks at 352, 640 and 691 nm corresponding to absorption from B-band and Q-band, respectively. The electrical properties obtained from ITO/Sn-doped MgPc/Al device suggest that the enhancement of the current flow in the doped device is a result from the increase of both carrier mobility and carrier concentration. Moreover, photoelectron analysis reveals two formations of Sn dopant in MgPc those are tin metal and derivative of tin oxide.