Tailoring the growth and electronic structures of organic molecular thin films

Understanding and control of heterointerfaces between organic and inorganic materials are critical for the development of organic electronics, molecular electronics, molecular/biological sensors, and energy harvesting devices. On the one hand, achieving large-scale molecular ordering on inorganic substrates remains a significant challenge that requires a thorough understanding of the growth mechanism. On the other hand, elucidating the charge behavior, electronic structures and energy-level alignment at the heterointerfaces are crucially important for enhancing the transport properties in hybrid devices. In this talk, I will discuss our recent discovery of the anisotropic crystalline step-flow growth of the prototypical metal phthalocyanine molecules on the deactivated Si(111)-B surface. I will then address the growth mechanism and show that the molecular ordering and molecular orientation can be effectively controlled through selective orbital coupling between the molecule and substrate. Finally, I will illustrate the effects of substrate electrostatic screening, mediated by interfacial charge transfer, on molecular electronic structures and energy-level alignment at the heterointerfaces.