ABSTRACT
Ultraviolet (UV)–ozone treatment on indium-tin-oxide (ITO) glass substrates has been widely used in the eld of organic optoelectronics for over several decades. ITO glass substrates are currently recognized as standard substrates for highefciency organic electronics devices. In the rst part of this chapter, however, we present evidence for rapid decay of common organic lms (e.g., NPB, Alq3, and rubrene) when they are in direct contact with UV-ozone-treated ITO (UV-ITO) substrates. Photoluminescence (PL), x-ray, and ultraviolet photoemission spectroscopies (XPS, UPS) are used to characterize the reliability of UV-ITO substrates. We conclude that the degradation of organic thin lms on UV-ITO substrates are mainly attributed to the active oxygen species generated upon UV-ozone treatments. The oxygen species behave as an oxygen reservoir that interacts with the adsorbed molecules by forming a gap state within its original bandgap and cause charge recombination.
