The role of thickness improvement and optimization in BMZO/Ag/BMZO sandwich transparent electrodes

Abstract

A BMZO (B–Mg co-doped ZnO)/Ag/BMZO multilayer film was prepared and studied via magnetron sputtering method. A continuous metal layer was formed by inserting a metal Ag layer between the two dielectric layers with a thickness of 15 nm, providing a complete conductive pathway. The electrical performance improved significantly, with a resistivity of 4.55 × 10⁻⁴ Ω cm. A metal-semiconductor heterojunction was formed at the interface, where electrons transferred from Ag to BMZO, creating an electron accumulation layer and improving carrier concentration and mobility. The average transmittance in the visible light region reached over 80 %. By optimizing the top BMZO layer thickness, the average transmittance of the composite film increased to 90 % while maintaining comparable electrical performance. XPS data analysis indicated that surface defects mainly originated from oxygen vacancies.