Fabrication And Properties Of Metal-oxide Composite Nanoglass Films

Unlike conventional amorphous materials without grain boundaries and dislocations,nanoglasses consist of amorphous nanoparticles and glass-glass interfaces,which results in unique properties.Its properties can further be controlled and improved by changing the chemical composition,particle size and interfacial volume fraction of the nanoglass.However,due to its difficult preparation methods,the systems reported so far are mostly metallic glass systems.The research direction of nanoglass focuses on thermal stability and mechanical properties,and its potential as a functional material remains to be explored.In this work,a new type of nanoglass materials was developed by multi-target magnetron co-sputtering method:metal(Cu)-oxide(ZrO₂)composite nanoglass film.Its microstructure,optical and electrical properties have been studied by using aberration-corrected transmission electron microscope,spectroscopic ellipsometry,UV-Visible spectrophotometer and Hall measurements.The main research findings are as follows:Cu-ZrO₂ nanoglass consists of Cu-doped ZrO₂ amorphous particles and a Cu-rich amorphous network.This material shows high visible light transmittance(over 70%),high refractive index(1.98 to 2.08)and wide optical band gap(5.0 to 5.7 e V).As the Cu content increases,the electrical properties are also improved.Cu_0.59(ZrO₂)_0.41nanoglass shows the most excellent electrical properties.The enrichment of Cu at the interface further provides a new route for the preparation of 2D nano-conducting networks.The deposited Cu_0.59(ZrO₂)_0.41 nanoglasses were annealed for 1 h at 300°C,400°C and 500°C,respectively.Below the crystallization temperature(300°C and400°C),as the annealing temperature increases,the width of the amorphous interface gradually increases and the real visible light transmittance of the material remains above 60%.At the same time,the conductivity of the annealed Cu_0.59(ZrO₂)_0.41 film is still improved even though some Cu elements are lost due to Cu surface precipitation during the annealing process,which is attributed to the enhanced precipitation of Cu atoms at the amorphous interface.The annealing temperature of 500°C,the Cu_0.59(ZrO₂)_0.41 film is completely crystallized,forming crystalline ZrO₂ particles and crystalline Cu network between the particles.