Controlled modification of Schottky barrier height by partisan interlayer

A comprehensible and systematic method to modify the Schottky barrier height (SBH), based on the adjustment of the semiconductor electron affinity through adsorbate termination, is demonstrated. Atomic layers of As and Cl, inserted at the metal-Si(111) interface and preferentially bonded to Si, are shown to shift the SBH by as much as 0.40 eV. The (partial) preservation of surface dipole at the metal-semiconductor (MS) interface is likely attributable to the chemical stability of adsorbate-terminated semiconductor surfaces. Experimental and theoretical results are presented to demonstrate the validity of the concept and the effectiveness of SBH adjustment through such partisan interlayers. The general implications of these results for the theoretical understanding and the practical control of the SBH are also discussed. (C) 2011 Elsevier Ltd. All rights reserved.