Optoelectronic Characterization Of In-doped ZnO Nanobelts With Different Doping Levels

One-dimensional ZnO nanomaterial has shown remarkable ultraviolet radiationperformance, surface polarization energy, high thermal stability, and high chemicalstability and so on. Comparing with pure ZnO, doped ZnO shows better electricconductivity, higher optical transparency, and higher thermal stability. Consequently, themanufacture and application of doped ZnO is the focus in the world, and doped ZnOhas shown great applied potential in nanoelectronic devices, optoelectronic devices, andnanoscale sensors, and other fields. Our works and results are as follows:1.ZnO nanobelts with different concentrations of In doping were synthesized bychemical vapor deposition （CVD） method. The morphology of the nanobelts wasinvestigated by Scanning Electron Microscopy （SEM）. In the X-Ray Diffraction （XRD）spectra, some peaks indexed to ZmlmOio have been shown while In-dopedconcentration rises to4.98%. The Raman spectra have been studied. The additional peakat614cm^-1 which can be connected with the formation of Zn₇In₂O₁₀ has been foundwhen In-doped concentration rises to4.98%, and the intensity of the peak is higher withthe increase of In-doped concentration.2.Micro-grid template method is used to fabricate Ohmic contact micro-electrodeof individual In-doped ZnO nanobelts devices. Several devices at each In-dopedconcentration were fabricated in order to obtain a universal law. The I-V characteristicsof these In-doped ZnO nanobelts with different In doping levels were measured bySemiconductor Device Analyzer （Agilent B1500A） in the atmosphere at roomtemperature. It is observed that the resistance of the nanobelts decreases with theincrease of In-doped concentration when In-doped concentration is more than3.91%.But the resistance of the nanobelts increases while In-doped concentration is more than3.91%. It can be seen that suitable In-doped concentration （about3.91%） can greatlyimprove the conductivity of ZnO nanobelts.3.In order to further discuss the optoelectronic characterization of In-doped ZnOnanobelts with different In doping levels, the photoresponses were measured. It is foundthat In-doped ZnO nanobelt is sensitive to UV illumination and the photocurrent cyclical variation with UV light on and off. The sensitivity of the devices is lower withthe increase of In-doped concentration, and the reset time becomes shorter.