Thermoelectric Properties, Phase Analysis, Microstructure Investigation and Lattice Parameters c/a Ratio of Al 3+ and In 3+ Substituted ZnO Sintered at High Temperature under Argon Atmosphere

Al2O3 and In2O3 co-doped Zinc oxide (ZnO) system have been studied for enhancing thermoelectric properties of ZnO. Al2O3 and In2O3 are doped with ZnO via solid-state solution method. The compositions were sintered at 1400°C in Argon atmosphere. The thermal and electrical properties of the system are investigated. The power factor of the order 481.8 μWK-2m-1 at 692.3°C and Seebeck coefficient of the order -133.99 μVK-1 at 691.4°C was obtained for the nominal formula (Zn1-x-yAlxIny)O, with x=0.02, y=0.05. It has been studied that power factor is a function of c/a ratio which is further a function of dopant concentration. The resistivities of all the compositions have been tuned and the lowest resistivity of the order 1.997 mΩ.cm at 692.3°C has been observed for the nominal formula (Zn1-x-yAlxIny) with x=0.02, y=0.01. These tuned resistivities will be helpful for future thermoelectric devices.