As technology advances and electronic devices evolve toward ultrathin and flexible architectures, the requirements for materials used in such applications become increasingly demanding. At the same time, the decreasing availability of indium resources in the Earth's crust is driving the search for alternative materials to replace conventional indium tin oxide (ITO) transparent electrodes. Consequently, current research efforts are focused on identifying materials and structures that can simultaneously meet the critical requirements of high optical transparency, electrical conductivity, chemical stability, and mechanical flexibility.

In this context, flexible, highly transparent, and conductive nitride/metal/nitride (NMN) electrodes based on SiN/Ag/SiN trilayer structures were fabricated on polyethylene terephthalate (PET) substrates using the high-power impulse magnetron sputtering (HiPIMS) technique. The influence of the individual layer thicknesses on the optoelectronic and mechanical properties of the NMN electrodes was systematically investigated. The optimized structure, designed as SiN₃₇/Ag₁₀/SiN₃₇, exhibited outstanding performance, achieving a maximum average transmittance of 99.4% in the visible range, a low sheet resistance of 2 Ω/□, and a high figure of merit at 550 nm (FoM₅₅₀ = 270 × 10⁻³ Ω⁻¹). Moreover, the electrode maintained its structural integrity and optoelectronic performance after 1000 mechanical bending cycles, confirming its excellent potential for application in flexible electronic devices.

These results highlight the potential of SiN/Ag/SiN as an efficient alternative to ITO as a transparent conductive oxide, offering superior optical transparency, electrical conductivity, and mechanical resilience. The findings pave the way for further advancements in the development of next-generation flexible transparent electronics, with potential applications in wearable devices, flexible displays, and optoelectronic systems.