Utilizing of high-pressure high-temperature synthesis to enhance the thermoelectric properties of Zn0.98Al0.02O with excellent electrical properties

• 来源期刊: 中国物理B（英文版）
• 年，卷（期）: 2021,（1）
• 页码范围: 442-449
• 页数: 8页
• 语种: 英文
• DOI: 10.1088/1674-1056/abc4dd

摘要

The temperature in the high-pressure high-temperature (HPHT) synthesis is optimized to enhance the thermoelectric properties of high-density ZnO ceramic, Zn0.98Al0.02O. X-ray diffraction, scanning electron microscopy, and transmission electron microscopy show that HPHT can be utilized to control the crystal structure and relative density of the material. High pressure can be utilized to change the energy band structure of the samples via changing the lattice constant of sam-ples, which decreases the thermal conductivity due to the formation of a multi-scale hierarchical structure and defects. Theelectrical conductivity of the material reaches 6×104 S/m at 373 K, and all doped samples behave as n-type semiconduc-tors. The highest power factor (6.42 μW·cm?1·K?2) and dimensionless figure of merit (zT =0.09) are obtained when Zn0.98Al0.02O is produced at 973 K using HPHT, which is superior to previously reported power factors for similar materi-als at the same temperature. Hall measurements indicate a high carrier concentration, which is the reason for the enhanced electrical performance.