Direct Observation of Dipole Influence Induced by a Spin Coated Organic Interfacial Layer on Effective Schottky Barrier Height Modulation of Hg/Si Contact

A thin organic interfacial layer fabricated by a spin coating method based on 80% ethoxylated polyethylenimine (PEIE) solution is demonstrated to be able to effectively modulate the Schottky barrier height (SBH) of Hg/Si contact. A 0.28 eV reduction of effective electron affinity for the PEIE coated Si is observed by Kelvin probe measurement, which directly reveals the dipole influence induced by the PEIE layer. Capacitance-voltage and current-voltage measurements further demonstrate that the SBH modulation is dominated by the interlayer dipole effect.