QUALITATIVE CHANGE OF THE ELECTRONIC-PROPERTIES OF A SEMICONDUCTOR SURFACE BY CHEMICAL TREATMENT USING POLYELECTROLYTES

In the present study we demonstrate the ability of changing the electr onic properties of a semiconductor surface by adsorbing polyelectrolyt es. For this purpose polyethylenimine (PEI) polymers were adsorbed ont o the van der Waals surface of the layered structure semiconductor WSe 2. For comparison the surface properties of the as grown and chemicall y treated surface were investigated by standard and photoassisted tunn eling spectroscopy. In the case of the chemically treated sample a str ong change in the I/V characteristics could be observed.