Effects of Al, Mo, and Ag Interlayers on the Optoelectronic Properties of SnO2/Metal/ZnO Multilayer Transparent Conductive Films

SnO 2 /metal/ZnO multilayer transparent conductive films incorporating Ag, Al, and Mo interlayers were fabricated by RF and DC magnetron sputtering to investigate the effects of interlayer metal selection on structural, electrical, and optical properties.Postdeposition vacuum annealing was performed at temperatures ranging from 200 to 500 ℃.Film thickness, crystallinity, carrier transport behavior, optical transmittance, grain size, and figure of merit (FOM) were systematically analyzed.X-ray diffraction results revealed enhanced crystallinity with increasing annealing temperature, accompanied by grain growth and phase evolution.Hall measurements indicated that optimal electrical performance was achieved by 200 ℃ annealing for Ag and Mo interlayers, with resistivities of 3.60 × 10 -2 and 4.02 × 10 -2 Ω•cm, respectively.Optical measurements showed an average visible transmittance exceeding 80% after 400 ℃ annealing for all samples.Among the investigated structures, the SnO 2 /Mo/ZnO film annealed at 200 ℃ exhibited the highest FOM of 9.42 × 10 -5 Ω -1 , demonstrating balanced electrical conductivity and optical transparency.The results confirm that appropriate interlayer engineering effectively enhances the optoelectronic performance of oxide/metal/oxide multilayer films for transparent electrode-and sensor-related applications.