The Researches On Current Saturation Properties Of ZnO Nanowire Schottky Barrier

In recent years, semiconductor nanomaterials show a broad prospect in the field of nanoscaleelectronic and optoelectronic devices such as transistors, photodetectors and sensors.As a kind of n-typesemiconductor material, the ZnO is an important optoelectronic material with wide bandgap of3.37eV andlarge exciton binding energy of60meV. One-dimensional nanostructures of ZnO have been widelyresearched on electrical and optoelectronic properties.And the fabrication of the electronic andoptoelectronic devices of them has been rapidly development. Among many types of nanoscale devices，Schottky device has many advantages. For example, Schottky photodiodes are attractive compared withother types of photodetectors due to their high response speed, low dark current, high responsivity and soon.In this paper, we show a unique current saturation characteristics of back to back Schottky prototypedevice. It has potential application value in the aspect of the development of nano rectifier deviceIn the first chapter, one-dimensional semiconductor material devices were introduced. Focusing onthe introduction of research progress ZnO nanowire Schottky device, we cleared the research content ofthis paper on this basis.In the second chapter, we synthesized uniform wurtzite ZnO nanowires with single crystal structure inthe Si substrate by using the chemical vapor deposition (CVD).Their surfaces contain rich oxygen vacancydefects.In the third chapter, we explored a sort of electron beam exposure process based on overlayoperation.It’s much easier to operate and positioned nanowires through an optical microscope.Then wefabricated ZnO nanowire prototype devices from bottom to top successfully by electron beam lithographybased on it. In this process, we explored the appropriate magnetron sputtering process parameters, so thatAu electrode and SiO2/Si substrate could be bonded better. And we studied the best way of lift-offIn the fourth chapter, we experimented on electrical transport properties test of single ZnO nanowiresschottky prototype device under normal temperature and pressure and found that current started tosaturation after the applied voltage reached a certain value for many devices, but this kind of saturation wasdifferent from reverse saturation current. So we analyzed the current transport properties by I-V-T. And then the mechanism of current saturation was analyzed. Saturation mechanism model is established. At thesame time, we expandly studied the current saturation properties, and discovered the bias needed forsaturation and saturation current changed with the bias step and the bias time.