The ITO transparent anode with a SnO2 layer (SnO2/ITO) serving as a buffer layer between the PEDOT: PSS has been prepared onto glass substrates. X-ray diffraction (XRD) shows that the SnO2 layer exhibits an amorphous structure. After the acid treatment, the resistivity of SnO2/ITO anodes was smaller than that of the acid-treated ITO anodes. Furthermore, the mechanism of the enhanced chemical stability by the SnO2 buffer layer is proposed. Such SnO2/ITO transparent anodes were used for organic solar cells (OSCs). The power conversion efficiencies (PCE) of OSCs used SnO2/ITO anodes with a SnO2 buffer layer thickness of 10 nm increased by 15% compared with the reference OSC used a bare ITO anode. (C) 2015 Elsevier B.V. All rights reserved.