Bicontinuous oxide heteroepitaxy with enhanced photoconductivity

Self-assembled nanocomposites present opportunities for a range of phase morphologies and desirable properties. Here authors present tuneable self-assembled nanostructures in the SnO2:NiO system; the double-percolated system expands the design of self-assembled oxides for practical applications, e.g. in optoelectronics. Self-assembled systems have recently attracted extensive attention because they can display a wide range of phase morphologies in nanocomposites, providing a new arena to explore novel phenomena. Among these morphologies, a bicontinuous structure is highly desirable based on its high interface-to-volume ratio and 3D interconnectivity. A bicontinuous nickel oxide (NiO) and tin dioxide (SnO2) heteroepitaxial nanocomposite is revealed here. By controlling their concentration, we fabricated tuneable self-assembled nanostructures from pillars to bicontinuous structures, as evidenced by TEM-energy-dispersive X-ray spectroscopy with a tortuous compositional distribution. The experimentally observed growth modes are consistent with predictions by first-principles calculations. Phase-field simulations are performed to understand 3D microstructure formation and extract key thermodynamic parameters for predicting microstructure morphologies in SnO2:NiO nanocomposites of other concentrations. Furthermore, we demonstrate significantly enhanced photovoltaic properties in a bicontinuous SnO2:NiO nanocomposite macroscopically and microscopically. This research shows a pathway to developing innovative solar cell and photodetector devices based on self-assembled oxides.

Automated summary

Authors have discovered tuneable self-assembled nanostructures in the SnO2:NiO system, which extends the design of self-assembled oxides for practical applications in optoelectronics. Self-assembled systems have recently attracted attention for their ability to display a wide range of phase morphologies in nanocomposites. By controlling their concentration, researchers have created tunable self-assembled nanostructures, confirmed through TEM-energy-dispersive X-ray spectroscopy. Phase-field simulations have been used to understand 3D microstructure formation and predict microstructure morphologies in SnO2:NiO nanocomposites of other concentrations. Additionally, significantly enhanced photovoltaic properties have been demonstrated in a bicontinuous SnO2:NiO nanocomposite.