Photoelectron spectroscopic study of iodine- and bromine-treated indium tin oxides and their interfaces with organic films

摘要

Work function variations of indium. tin oxide (ITO) treated with solutions of iodine and bromine as well as bromine vapor were studied by ultraviolet and X-ray photoelectron spectroscopies. Interfaces between the treated ITO and NPB were also investigated. Treatments by iodine and bromine solutions, and bromine vapor led to work function increase by as much as 0.6, 0.7, and 0.9 eV, respectively. After the halogen treatments, the hole-injection barrier for the NPB/ITO contact was remarkably decreased. A light-emitting device fabricated with bromine vapor-treated ITO as anode clearly demonstrated better hole injection at the ITO/NPB interface and a lower drive voltage. (C) 2003 Elsevier Science B.V. All rights reserved. [References: 23]