Probe the Effects of Surface Adsorbates on ZnO Nanowire Conductivity using Dielectric Force Microscopy  

介电力显微镜探测氧化锌纳米线表面吸附分子对电导率的影响

作　　者：陈琪[1,2] 卢威[2] 吴昱昆[3] 丁怀义[3] 王兵[1] 陈立桅[2] 

机构地区：[1]中国科学技术大学合肥微尺度物质科学国家实验室(筹),合肥230026 [2]中国科学院苏州纳米技术与纳米仿生研究所纳米研究国际实验室,苏州215123 [3]中国科学技术大学物理系,合肥230026

出　　处：《Chinese Journal of Chemical Physics》2014年第5期582-586,I0004,共6页化学物理学报（英文）

摘　　要：Characterization of electric properties of nanomaterials usually involves fabricating field effect transistors （FET） and deriving materials properties from device performances. However, the quality of electrode contacts in FET devices heavily influences the device performance, which makes it difficult to obtain the intrinsic electric properties of nanomaterials. Dielectric force microscopy （DFM）, a contactless method developed recently, can detect the low-frequency dielectric responses of nanomaterials without electric contact, which avoids the influence of electric contact and can be used to study the intrinsic conductivity of nanomaterials. Here we study the influences of surface adsorbates on the conductivity of ZnO nanowires （NWs） by using FET and DFM methods. The conductivity of ZnO NW is much larger in N2 atmosphere than that in ambient environment as measured by FET device, which is further proven by DFM measurement that the ZnO NW exhibits larger dielectric response in N2 environment, and the influence of electrode contacts on measurement can be ruled out. Based on these results, it can be concluded that the adsorbates on ZnO NW surface highly influence the conductivity of ZnO NW rather than the electrode contact. This work also verifies the capability of DFM in measuring electric properties of nanomaterials.

关 键 词：Dielectric force microscopy ZnO nanowire Field-effect transistor Surface adsorbate 

分 类 号：O[理学]