• Energy Research

Nanomaterials can be game-changers in the arena of sustainable energy production because they may enable highly efficient thermoelectric energy conversion and harvesting. For this purpose, doped thin film oxides have been proven to be promising systems for achieving high thermoelectric performances. In this work, the design, realization, and experimental investigation of the thermoelectric properties exhibited by a set of five Al:ZnO thin films with thicknesses of 300 nm and Al doping levels ranging from 2 to 8 at.% are described. Using a multi-technique approach, the main structural and morphological features of the grown thin films are addressed, as well as the electrical and thermoelectrical transport properties. The results show that the samples exhibited a Seebeck coefficient absolute value in the range of 22–33 μV/K, assuming their maximum doping level was 8 at.%, while the samples’ resistivity was decreased below 2 × 10−3 Ohm·cm with a doping level of 3 at.%. The findings shine light on the perspectives of the applications of the metal ZnO thin film technology for thermoelectrics.

We present recent results obtained with a novel spectrometer developed within the EU projectVOLPE (VOLume PhotoEmission from solids with synchrotron radiation), now operational at ESRF (Beamline ID16), where we were able to achieve high energy resolution as well as good statistics photoemission spectra up to 6–8 keV of photoelectron kinetic energy. The spectrometer is a hemispherical deflector analyzer with electrostatic input lens and 2D position sensitive detector. Ag 3d, Au 4f and valence band spectra have been measured from polycrystalline Ag and Au, displaying an overall energy resolution (photons + analyzer) of about 71 meV at 6 keV, as measured at 18K on the Fermi edge. The corresponding resolving power of 8×104 is one of the highest values achieved in photoemission measurements from solid samples.