Surface analysis of LiBq4/ITO and LiBq4/CuPc/ITO using atomic force microscopy and x-ray photoelectron spectroscopy

Abstract

We have investigated the surfaces of the samples LiBq4/ITO and LiBq4/CuPc/ITO. The atomic force microscopy (AFM) observations indicate that different surface morphologies are formed on different substrates, and what is more, x-ray photoelectron spectroscopy is also utilized to further demonstrate the AFM results. It is concluded that the introduction of a CuPc buffer layer under the LiBq4 layer can improve the film quality of LiBq4, and the improvement should be attributed to the differences in molecular structure and electron affinity.