Characterisation of Organic Semiconductor Growth using Real-time Electron Spectroscopy

An organic molecular beam deposition system coupled to a soft x-ray excitation source has been developed to monitor the growth of organic semiconductor thin films in-situ and in real-time. Rapid collection of photoelectron spectra has been enabled using a multichannel array detector coupled to a hemispherical analyzer. The organic semiconductor tin phthalocyanine (SnPc) exhibits a Stranski-Krastanov growth mode on a polycrystalline gold substrate where the transition thickness between layered and clustered growth has been determined to be comparable to the thickness of a single molecular layer within which the molecules are standing on edge relative to the substrate plane.