Sub-micrometer Pyroelectric Tomography of AlScN Films

We report on one- to three-dimensional characterization of the pyroelectric properties of aluminum scandium nitride. By means of the laser intensity modulation method, we reconstructed the in-depth distribution of the spontaneous polarization with sub-micrometer resolution. The reconstructed profiles of the spontaneous polarization indicate that the thermal diffusivity and its temperature-dependence differ significantly from what is reported for pure aluminum nitride, which we attribute to the dominant role of phonon-alloy scattering for the heat transfer.