采用固相反应法制备了六方纤锌矿结构Zn1-xAlxO(0≤x≤0.005)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.Al掺杂促使ZnO晶粒长大联结,晶界减少,x=0.005时出现在晶界分布的ZnAl2O4尖晶石相.各组分样品经二次烧结后,电阻率均比对应组分的一次烧结样品增大1~2个数量级.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,一次烧结样品在x=0.004有最小的室温电阻率~10 mΩ·cm,主要由于掺杂使样品载流子浓度和迁移率显著提高;300~950 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=0.004时有最大的室温功率因子~0.11 mW/m·K2.综合得到ZnO中Al掺杂的饱和固溶度在0.004~0.005之间.
Zn1-xAlxO(0≤x≤0.005) polycrystalline bulks with hexagonal wurtzite structure were prepared by solid-state reaction method.The micro morphology and the thermoelectric properties of Zn1-xAlxO bulk were investigated.Doping Al made ZnO grain increased and grain boundary decreased.The results show that the spinel ZnAl2O4 appeared while x=0.005.Secondarily sinterd samples have 1-2 orders of magnitude decrease of resistivity.The semiconductor behavior of bulks transform metallic behavior after Al doping in ZnO.Al doping is responsible for the carrier concentration and mobility remarkable increase.At x=0.004 the minimum of resistivity of primarily sintered sample is 10 mΩ·cm.The seebeck coefficient and power factor S2/ρ increase with the increasing temperature at 300-950 K.The maximum of the power factor is 0.11 mW/m·K2 at room temperature.The saturated solution of Al doping in ZnO is between 0.004 and 0.005.
参考文献
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%