Development of n-type ZnAlInO Semiconductor Materials for Thermoelectric Generators in Aerospace Applications

Thermoelectric conversion is a system that can convert heat energy originating from temperature difference into electrical energy. Although it has many advantages in terms of usage, research is required to acquire high-efficiency thermoelectric materials due to their low efficiency. Herein, Al- and In-doped ZnO semiconductor thermoelectric material is synthesized, produced, and examined for use in the production of thermoelectric generators that can be used in aviation applications. The synthesis of ZnAlIn powders is carried out by the sol-gel method. The xerogel is dried at 200 °C for 10 h, and the dried material is then calcined at 600 °C for 4 h in an atmospheric oven to obtain ZnAlIn material. The obtained powder is then compressed with a cold press to produce pellet samples. Pellet samples are sintered in an atmospheric furnace at 1350 °C for 36 h and are made ready for measurements. Comprehensive characterization and analysis of microstructural and structural properties are performed by Fourier transform infrared spectroscopy, differential thermal analysis-thermogravimetry, X-ray photoelectron spectroscopy, scanning electron microscopy, and X-ray diffraction methods. Seebeck coefficient and thermal capacity measurements are performed to determine thermoelectric properties. The results obtained from the study show that ceramic-based ZnAlIn semiconductor thermoelectric material has the required efficiency for thermoelectric generator production.