a Center for Microelectronics Research, Department of Electrical Engineering, University of South Florida, Tampa, FL 33620, USA
b Optical Sciences Division, US Naval Research Laboratory, Washington, DC 20375, USA
Abstract:
We determined the work function of indium tin oxide (ITO) films on glass substrates using photoemission spectroscopy (PES). The ITO coated glass substrates were chemically cleaned ex-situ, oxygen plasma treated ex-situ, or sputtered in-situ. Our results suggest that the performance of ultraviolet photoemission spectroscopy (UPS) measurements can induce a significant work function reduction on the order of 0.4–0.5 eV, on ex-situ chemically and oxygen-plasma treated ITO samples. This was demonstrated by the use of low intensity X-ray photoemission spectroscopy (XPS) work function measurements before and after the UPS measurements were carried out.