Gold/Molecule/p $^+$ Si Devices: Variable Temperature Electronic Transport

Although a considerable amount of experimental and theoretical work has been devoted to nanoelectronic systems with molecular components, relatively little work has been done on molecular electronic devices on technologically relevant substrates such as silicon. Metal-molecule-semiconductor (MMS) studies have generally focused on structures in which the semiconductor barrier is dominant or treated the semiconductor as a metallic contact. In this paper, we present measured temperature-dependent current-voltage characteristics of gold/molecular monolayer/p⁺ silicon devices. We explore how the bandstructure of the degenerately doped semiconductor, molecular electronic properties, surface states, and molecular vibronic properties contribute to the electronic transport. We also demonstrate that molecule-dominated behavior can be achieved in a MMS device by appropriate engineering of the contact electronic properties.