The Influence Of ZnO Nanomaterials Characteristics Under A Longitudinal Electric Field

Zinc oxide (ZnO), a II-VI oxide semiconductor with a wide direct band gap (3.37eV)and a large exciton binding energy (60meV) at room temperature, has been considered as apotential candidate material for short-wavelength optoelectronic applications, especially forblue to ultraviolet (UV) light emitting diode (LED) and UV detector devices. The structuredefects and surface defects of ZnO were produced in the preparation process, which wasinfluence on the luminescent properties. Therefore, to explore the visible region of the defectand the ZnO luminescent mechanism caused by the deep level defects to the UV lightemitting device will obtain high become an important task of researchers. For the hexagonalstructure of ZnO, ZnO along the c-axis direction with a strong polarity, so in the appliedelectric field the surface morphology and optical properties of ZnO materials will change. Inthe paper the surface morphology, structural, optical characteristics of ZnO were studiedunder a longitudinal electric field. Furthermore, the Sb-doped p-ZnO nanowires/n-ZnOnanowires homojunction LED was successfully fabricated. The major research a chievementsare listed below:(1) The ZnO structures with different morphologies were grown on Si (111) substrates bychemical vapor deposition method under the different longitudinal electric field. The FE-SEMshowed that the morphologies of samples were changed from worse orientation nanorods tonanorods with better orientation and to thin film with increasing longitudinal electric field.Furthermore, the optimal longitudinal electric field for ZnO nanorods is40V. The sample F oflongitudinal electric field50V was optimal annealing at800℃in the oxygen atmospheric,and the visible luminescence may be related with the oxygen vacancies.(2) The Sb-doped ZnO nanowires/n-ZnO nanowires/n-Si homojunctions weresynthesized by simple chemical vapor deposition method under a longitudinal electric field40V. The FE-SEM showed that the n-ZnO and p-ZnO nanowires were connected veryperfectly. Moreover, The properties of the homojunction photoelectric device have beeninvestigated. It shows that this device has good rectifier characteristics. The device realizedthe electroluminescent at room temperature at positive35mA of the injection of currentconditions. The electroluminescence spectrum was obtained on the ZnO nanowireshomojunctions at room temperature with a ultraviolet emission peak at3.24eV and a visible band centered at2.49eV.