Thermally Enhanced Secondary Electron Emission Enables High-Flux and Low-Damage Sputtering Deposition of Soft-Lattice Perovskite Films

Developing scalable, low-cost, and high-throughput vapor-phase deposition is essential for advancing soft-lattice hybrid perovskite optoelectronic devices toward commercial manufacturing. However, rapid vapor-phase deposition often requires high external energy input, which can destabilize the soft lattice, causing organic-component degradation, compositional drift, and structural disorder. Here, we propose a low-power thermal sputtering strategy based on enhanced electron emission. Target self-heating facilitates secondary electron emission and sustains high-density plasma under moderate power input, enabling rapid deposition of perovskite films with reduced plasma-induced damage. In situ optical emission spectroscopy further enables real-time monitoring of sputtering rate and organic-component degradation during deposition. Compared with conventional high-power deposition, films prepared by low-power thermal sputtering exhibit higher phase purity and improved lattice ordering, leading to enhanced photodetector responsivity and stability. This work provides mechanistic insights and a practical foundation for the high-speed, low-damage vapor deposition of soft-lattice semiconductor films.