Dependence of aluminum-doped zinc oxide work function on surface cleaning method as studied by ultraviolet and X-ray photoelectron spectroscopies

▶ Both acetone solvent and UV-ozone cleaning enhance AZO work function. ▶ UV-ozone treated AZO achieves relative higher work function of 4.26 eV. ▶ Stoichiometry ratio and carbon contamination affect AZO work function, and the stoichiometry ratio is the controlling factor. ▶ AZO with high stoichiometry ratio and reduced carbon concentration possesses high work function.