Abstract: Currently, the synthesis of nanostructures still encounters two grand challenges: one is the often-required high temperatures and/or high pressures, and the other is the scalable fabrication. Here, to break through such bottlenecks, we demonstrate an ambient-condition strategy for rapid mass production of fourth-generation semiconductor Ga₂O₃ nanoarchitectures assembled by single-crystalline nanosheets in a controlled manner based on sonochemistry. Their growth is fundamentally determined by the introduced ethanediamine in rationally designed source materials, which could not only protect the metal Ga against reacting with H₂O into GaOOH, but facilitate the reaction of Ga with OH· radicals for target crystalline Ga₂O₃ nanostructures. As a proof of concept for applications, the as-fabricated Ga₂O₃ nanoarchitectures exhibit superb performances for electromagnetic wave absorption with a reflection loss value of 52.2 dB at 8.1 GHz, and ammonia sensing with high sensitivity and selectivity at room temperature, representing their bright future to be commercially applied in modern devices.

Key words: Semiconductor, Crystalline nanostructures, Crystal growth, Ambient condition, Device application