Ultralow-Temperature Solution-Processed Aluminum Oxide Dielectrics via Local Structure Control of Nanoclusters

Oxide dielectric materials play a key role in a wide range of high-performance solid-state electronics from semiconductor devices to emerging wearable and soft bioelectronic devices. Although several previous advances are noteworthy, their typical processing temperature still far exceeds the thermal limitations of soft materials, impeding their wide utilization in these emerging fields. Here, we report an innovative route to form highly reliable aluminum oxide dielectric films using an ultralow-temperature (<60 °C) solution process with a class of oxide nanocluster precursors. The extremely low-temperature synthesis of oxide dielectric films was achieved by using low-impurity, bulky metal-oxo-hydroxy nanoclusters combined with a spatially controllable and highly energetic light activation process. It was noteworthy that the room-temperature light activation process was highly effective in dissociating the metal-oxo-hydroxy clusters, enabling the formation of a dense atomic network at low temperature. The ultralow-temperature solution-processed oxide dielectrics demonstrated high breakdown field (>6 MV cm^-1), low leakage (∼1 × 10^-8 A cm^-2 at 2 MV cm^-1), and excellent electrical stability comparable to those of vacuum-deposited and high-temperature-processed dielectric films. For potential applications of the oxide dielectrics, transparent metal oxides and carbon nanotube active devices as well as integrated circuits were implemented directly on both ultrathin polymeric and highly stretchable substrates.