Researchers engineered aluminum scandium nitride thin films to reach a piezoelectric coefficient of 15.0 pC N−1 and an electromechanical coupling rate of 34.9%, according to a study published in Nature Communications. The team applied post-growth rapid thermal annealing to Al0.9Sc0.1N films as part of a multi-scale lattice engineering method aimed at lead-free piezoelectric applications.
The measured performance gain stems from a reduced c/a lattice ratio combined with homogenized nanodomain alignment. Nature Communications reported that this structural shift is fundamentally driven by a transition toward higher bond ionicity, which was demonstrated by a reduced minimum electron density at the bond saddle points.
Fabrication tests scaled the material to an industrial-grade 6-inch wafer process. The resulting microelectromechanical systems (MEMS) chip operated at a resonant frequency of 368.2 kHz, delivering an acoustic sensitivity of −162.4 dB at 10 Hz alongside a noise floor of 59 dB at 1 kHz. Testing confirmed operational stability across multiple media types and thermal conditions up to 150 °C.
Zhenyue Cheng, Tong Liu, and Daojian Su contributed equally to the study as primary authors. The research involved teams from the University of Jinan, Shandong University, Laoshan Laboratory in Qingdao, and the University of Wollongong in Australia, with funding from the National Natural Science Foundation of China and research programs across Shandong Province.
