Organic solar cells based on small molecules and conjugated polymers are attracting much attention due to their merits of low costs,simple fabrication processes,light weights,and mechanical flexibilities.Metals are usually considered as promising candidates for the semi-transparent electrodes.In such devices,a strong microcavity resonance can be supported between the two electrodes,resulting in a narrowed bandwidth of light absorption,which,unfortunately,will lower the performances of organic solar cells si...