Thermoelectric microgenerators using a single large-scale Sb doped ZnO microwires

The large-scale ZnO microwires (MWs) arrays with different Sb doping concentrations were grown by chemical vapor deposition method without using metal catalyst or seed layer. The diameter and length of MWs were about 20-50 μm and 1-2.5 cm, respectively. The experimental results indicated that the length and orientation of ZnO MWs were improved gradually with increasing Sb concentration. The surfactant effect of Sb should be the major improvement reason. Furthermore, thermoelectric microgenerators based on single Sb doped ZnO MW have been fabricated on a glass substrate, which can generated maximum output voltage of 68 mV and maximum output current of 782 nA under a temperature difference of 20 K between the two electrodes. The single Sb doped ZnO MW showed a Seebeck coefficient of about 3.4 mV/K. In addition, the output current of the device was increased dramatically in ultraviolet (UV) illumination compared to dark conditions. The detail of the UV irradiation enhanced output properties of microgenerator was also discussed.