Thermoelectric Properties of MOVPE Grown AlInN, Lattice-Matched to GaN

In this work, we investigate experimentally the growth and thermoelectric properties, i.e., thermal conductivity, Seebeck coefficient, and electrical conductivity, of n-type wurtzite high quality Al$_{x}$In$_{1-x}$N, grown on GaN template on sapphire substrate by MOVPE, in-plane lattice-matched to GaN. The thermal conductivity is measured by 3$\omega $ method differential technique for thin films. The thermal conductivity value of Al$_{0.83}$In$_{0.17}$N is measured as 5.7 W/(mK). The Seebeck coefficient is calculated as the ratio of measured voltage difference and temperature difference when a temperature gradient is created in the sample. The absolute Seebeck coefficient value of Al$_{0.83}$In$_{0.17}$N is measured as 6.2$\times $10$^{-4}$ V/K. The sheet resistivity of lattice-matched Al$_{0.83}$In$_{0.17}$N is measured using Van der Pauw scheme and the electric conductivity is acquired accordingly to be 2.9$\times $10$^{4}$ /($\Omega $.m). The Z*T value of Al$_{0.83}$In$_{0.17}$N obtained is above 0.2 at room temperature. The results indicate AlInN based alloys are good candidates for thermoelectric devices.