Enhanced thermoelectric performance of Al-doped ZnO thin films on amorphous substrate

Abstract

2% Al-doped ZnO (AZO) thin films fabricated at 300 °C by pulsed laser deposition (PLD) on amorphous fused silica demonstrated the high quality crystallinity and grain connection, which correlates to the high thermoelectric performance: electrical conductivity σ = 923 S/cm and Seebeck coefficient S = −111 µV/K at 600 K. Its power factor (S2 · σ) is 1.2 × 10−3 W m−1 K−2, twofold better than films deposited on crystalline SrTiO3 under the same experimental conditions. Using our measured thermal conductivity (κ) at 300 K (4.89 W m−1 K−1), the figure of merit, ZT = (S2 · σ · T/κ), is calculated as 0.045 at 600 K, 5 times larger than ZT of our previously reported bulk ZnO.