Enhanced Optical, Electrical and Dielectric Properties of WO₃ Stacks Via Indium Nanosheets

Abstract This study investigates the effect of inserting 50 nm and 100 nm indium nanosheets between tungsten oxide layers to create WO 3 /In/WO 3 (WIW) films. Fabricated by vacuum evaporation, these amorphous WIW films showed a 62% reduction in average surface roughness. Indium nanosheets enhanced optical properties, increasing visible and infrared light absorption by 256% at 3.0 eV and 224% at 1.76 eV, while reducing the energy bandgap from 2.94 to 2.11 eV with thicker nanosheets. WIW films exhibited enhanced dielectric and optical conductivity responses leading to an improved terahertz cutoff frequencies values of 1.6–9.6 THz in the light range of 1.13–3.0 eV. Electrical resistivity dropped by two and four orders of magnitude for 50 and 100 nm layers, respectively. These combined improvements make WIW films promising for electro‐optical applications.