Significant Enhancement of Piezoelectric Properties in MgHf Highly Co-Doped AIN Thin Films for Advanced Sensors and Microgenerators

This paper presents a comprehensive study on a high-throughput development and characterization of combinatorial (MgHf)
x
Al
1-x
N films, showcasing their exceptional piezoelectric properties and impressive Figure of Merit (FOM) for applications in sensors and microgenerators. Through the development of (MgHf)
x
Al
1-x
N films, we successfully achieved a high piezoelectric coefficient (d
31
) of 6.8 pm/V, which is three times higher than that of pure AlN (2.3 pm/V). Consequently, the FOM reached 31.5 GPa at
$x=0.44$
representing a fivefold increase compared to that of pure AlN (approximately 6.5 GPa) and a 1.5-fold improvement over that of PZT (approximately 20 GPa).