The characteristics of organic light-emitting diodes (OLEDs) with aluminum phthalocyanine chloride (AlPcCl) as an anode buffer layer were investigated. The basic structure of OLED is indium-tin oxide (ITO)/N,N'-di(naphth-2-yl)-N,N'-diphenyl-benzidine (NPB)/tris(8-hydroxyquinoline) aluminum (Alq(3))/lithium fluoride (LiF)/aluminum (Al). AlPcCl inserted at the ITO/NPB interface as an anode buffer layer can enhance hole injection, and thus current density, luminance as well as efficiency. Based on the energy level and Richardson-Schottky (R-S) thermionic emission theory, the enhanced performance can be explained. Additionally, the effect of the deposition rate of AlPcCl on the device performance was also examined. The results show that the optimal deposition rate of AlPcCl is 0.05 nm/s. (C) 2013 Published by Elsevier Ltd.