摘要
Interface/surface properties play an important role in the development of most electronic devices. In particular, nanowires possess large surface areas that create new challenges for their optoelectronic applications. Here, we demonstrated that the piezoelectric field and UV laser illumination modulate the surface potential distribution of a bent ZnO wire by the Kelvin probe force microscopy technology. Experiments showed that the surface potential distribution was changed by strain. The difference of surface potential between the outer/inner sides of the ZnO wire increased with increasing strain. Under UV laser illumination, the difference of surface potential between the outer/inner sides of the ZnO wire increased with increasing strain and illumination time. The origin of the observed phenomenon was discussed in terms of the energy band diagram of the bent wire and adsorption/desorption theory. It is suggested that the change of surface potential can be attributed to the uneven distribution of the carrier density across the wire deduced by the piezoelectric effect and surface adsorption/desorption of oxygen ions. This study provides an important insight into the surface and piezoelectric effects on the surface potential and can help optimize the performance of electronic and optoelectronic devices. [Figure not available: see fulltext.] © 2016, Tsinghua University Press and Springer-Verlag Berlin Heidelberg.
Interface/surface properties play an important role in the development of most electronic devices. In particular, nanowires possess large surface areas that create new challenges for their optoelectronic applications. Here, we demonstrated that the piezoelectric field and UV laser illumination modulate the surface potential distribution of a bent ZnO wire by the Kelvin probe force microscopy technology. Experiments showed that the surface potential distribution was changed by strain. The difference of surface potential between the outer/inner sides of the ZnO wire increased with increasing strain. Under UV laser illumination, the difference of surface potential between the outer/inner sides of the ZnO wire increased with increasing strain and illumination time. The origin of the observed phenomenon was discussed in terms of the energy band diagram of the bent wire and adsorption/desorption theory. It is suggested that the change of surface potential can be attributed to the uneven distribution of the carrier density across the wire deduced by the piezoelectric effect and surface adsorption/desorption of oxygen ions. This study provides an important insight into the surface and piezoelectric effects on the surface potential and can help optimize the performance of electronic and optoelectronic devices. [Figure not available: see fulltext.] © 2016, Tsinghua University Press and Springer-Verlag Berlin Heidelberg.
基金
This work was supported by the National Basic Research Program of China (No.2013CB932602),the Program of Introducing Talents of Discipline to Universities (No.B14003),National Natural Science Foundation of China (Nos.51527802,51232001,and 51572025),Beijing Municipal Science & Technology Commission,the Fundamental Research Funds for Central Universities,State Key Laboratory for Advanced Metals and Materials.
