Abstract
Owing to the scarcity of indium element and the natural brittleness of tin doped indium oxide (ITO), several emerging transparent and conductive electrodes (TCEs) including metal oxides, carbon nanotubes, graphene, metallic nanowire networks and metal grids have been developed recently. One of them is the silver nanowires (Ag NWs) network TCE that can be considered as the most promising candidate for replacing commercial ITO due to their non-toxicity and easy preparation. We report an Ag NWs TCEs embedded into PMMA by pressing can be used as a high quality TCEs with lower sheet resistance and good transmittance for optoelectronic devices. The sheet resistance (Rsheet) of Ag NWs/PMMA composite TCEs can be remarkably reduced from 36k (Ω/□) to 40 (Ω/□) comparing with the pure Ag NWs network and its transmittance reached to 93.8% (@550 nm). The pressing process, not only greatly improved contact junction between NWs with outstanding reduction of sheet resistance owing to larger and more effective contact areas, but also decreased the surface roughness of the composite transparent electrode, which dominates performances of OLED devices. In addition, we successfully demonstrated an approach to transfer Ag NWs network onto various flexible substrates including PEN, PI and papers. After 10000 bending tests with a curvature radius of 2mm, Ag NWs/PMMA composite electrode on PI and PEN substrates exhibited better mechanical flexibility with low sheet resistances of ~42 (Ω/□) for PI and ~91 (Ω/□) for PEN. By utilizing this Ag NWs TCEs as the anode in ITO-free organic light emitting diodes (OLEDs), promising performance of 85.9 lm W−1 power efficiency and 19.9% external quantum efficiency is demonstrated, compared with the ITO case of 80.1 lm W−1 and 19.2%. Finally, we have demonstrated flexible high conversion efficiency CIGS solar cells with a hybrid TCE of AZO/Ag NWs/AZO (called AAA films). Based on the results of bending test, the flexible CIGS cell with AAA films also exhibited better device performance nearly without decay.