Organic probe for inhomogeneous band bending

Abstract

The initial stage of 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) adsorption on Se-passivated n-type GaAs(100)-(2×1) surface was investigated using high-resolution soft x-ray photoemission spectroscopy. A very small amount of PTCDA (≪1 ML) is sufficient to induce a reduction of inhomogeneous band bending at the surface as judged from the sharpening of the core level spectra. This is interpreted in terms of preferential sticking of the organic molecules to surface defects. The results presented in this letter indicate that organic molecules may also serve as very suitable probes for inorganic semiconductor surface evaluation through the photoemission studies.