Highly flexible ZnO/Ag/ZnO conducting electrode for organic photonic devices

We investigated the electrical, optical and bending characteristics of ZnO (40 nm)/Ag (18.8 nm)/ZnO (40 nm) multilayer film deposited on polyethylene terephthalate (PET) substrate and compared them with those of indium-tin-oxide (ITO) (100 nm thick). The ITO single and ZnO/Ag/ZnO multilayer films gave maximum transmittance of 92.9% and ~95% at ~530 nm, respectively. For the ITO single and ZnO/Ag/ZnO multilayer films, the carrier concentration was measured to be 1.19×1020 and 6.68×1021 cm−3, respectively and the mobility was 32.06 and 21.06 cm2/V s, respectively. The sheet resistance was 175.99 and 4.98 Ω/sq for the ITO single and ZnO/Ag/ZnO multilayer films, respectively. Haacke׳s figure of merit (FOM) of the ITO single and ZnO/Ag/ZnO multilayer films was calculated to be 2.36×10−3 and 104.5×10−3 Ω−1. The ZnO/Ag/ZnO multilayer films showed dramatically improved mechanical stability when subjected to bending test.