采用固相反应法制备了六方纤锌矿结构Zn1-xAlxO(0≤x≤0.03)系列多晶,探究了Al掺杂对ZnO多晶的微观形貌和热电输运性质的影响.结果表明,Al掺杂促使ZnO晶粒长大联结,晶界减少,x＞0.003时出现在晶界分布的ZnAl2O4尖晶石相.掺杂后样品由ZnO的半导体行为转变为电阻率显著下降的金属行为,且x=0.003有最小的室温电阻率～1.7 mΩ·cm,主要由于掺杂使样品载流子浓度和迁移率显著提高,x=0.003时载流子浓度和迁移率为最高,分别为1.05×1021 cm-3和20 cm2/V·s;300 ～900 K下掺杂样品热电势的绝对值和功率因子均随温度升高而增大,x =0.003时有最大的室温功率因子～0.4mW/m·K2.综合得到ZnO中Al掺杂的饱和固溶度x≈0.003.
Zn1-x AlxO (0 ≤ x ≤ 0.005) polycrystalline bulks with hexagonal wurtzite structure were prepared by solid-state reaction method.The microstructure and thermoelectric properties of Zn1-xAlxO bulk were investigated.Doping Al makes ZnO grain increases and grain boundry decreases.The results show that the spinel ZnAl2 O4 appeared while x ＞ 0.003.The semiconductor behavior of bulks transform metallic behavior after Al doping in ZnO.Al doping is responsible for 1 orders of magnitude decrease of resistivety and the carrier concentration and mobility remarkable increase.At x =0.003 the minimum of resistivety is 1.7 mΩ · cm and the carrier concentration and mobility are maximum.The carrier concentration is 1.05 × 1021 cm-3.The mobility is 20 cm2/V · s at room temperature.The seebeck coefficient and power factor S2/p increases as the temperature increasing at 300-900 K.The maximum of the power factor is 0.4 mW/m · Ks at room temperature.The saturated solution of Al doping in ZnO is 0.003.
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