Piezoelectric Hafnium Oxide Thin Films for Energy-Harvesting Applications

This paper presents the piezoelectric properties of silicon doped hafnium oxide (Si:HfO2) thin films and their superior suitability for energy harvesting applications. Various layer thicknesses from 10 nm to 50 nm, executed as single layer and in a laminate structure, are investigated. The piezoelectric coefficient d
_33,f
of the samples is measured via double beam laser interferometry (DBLI) and converted into d
₃₃
, based on a numerical simulation model. Values of up to d
₃₃
=73 pm/V are obtained. Finally, the Si:HfO
₂
films are electrically investigated by evaluating a relative permittivity between 37 and 47, respectively.