Organic–Inorganic Hybrid Structure as a Conductive and Transparent Layer for Energy and Optoelectronic Applications

In the era of hybrid organic devices, solution-processed metal-embedded polymer multilayer structures are potential candidates for transparent electrode applications. Here, an organic–inorganic–organic (OIO) layered structure has been fabricated as a metal oxide-free transparent conducting electrode, where a thin metal layer (Ag) was sandwiched between two organic polymer (polystyrene) layers. The metal layer was deposited by the DC sputtering technique, and the polymer layers were deposited by an easy and efficient dip coating technique with good thickness control. The thickness of the middle Ag film was varied from 4 to 30 nm to investigate its effect on the transparency and conductivity of the multilayered structure. The morphological behavior shows that a higher thickness of Ag gives a continuous layer formation and a smooth top surface of the layered structure, which is a vital feature of a good electrode. The results of various investigations of the OIO structure show promising optoelectrical performance for its applicability in transparent and flexible optoelectronics. Depth profiling in X-ray photoelectron spectroscopy (XPS) revealed that the Ag layer retains its metallic form mostly and only a small amount gets oxidized when exposed to the environment. In spite of the formation of silver oxide, an electrical resistivity of 1.1 × 10–4 Ω cm with an optical transparency of ∼75% was obtained in the OIO structure for an 8 nm thickness of the Ag layer. The key findings of the present investigations demonstrate a facile, low-cost, and effective method with a rational design for the fabrication and application of a transparent conducting electrode, which can be an alternative to indium tin oxide (ITO).