Controllable Synthesis Of Ternary ZnS_xSe_1-x Nanowires With Tunable Band-gaps For Optoelectronic Applications

One-dimensional?1D?inorganic nanostructures such as nanowires?NWs?,nanobelts?NBs?,and nanorods?NRs?have attracted extensive attention in past decades,due to their great importance in basic scientific research and potential applications.II-VI group 1D nanostructures have suitable direct band-gaps from 1.5eV?CdTe?to 3.7 eV?ZnS?,which offer a flexibility to design and fabricate optoelectronic devices to work on various wavelengths of choice.Among II-VI group nanomaterials,ZnSe and ZnS have been intensively studied and regarded as promising optoelectronic materials for a host of optoelectronic applications due to their wide direct band-gaps and bipolar doping capability,However,their constant band-gaps limit their further applications in optoelectronic devices.Therefore,the development of controllable synthesis of ternary ZnS_xSe_1-x one dimensional nanostructure with tunable band-gaps method and explore their applications in optoelectronic devices is of great importance.ternary ZnS_xSe_1-x nanowires?NWs?with tunable band-gaps were synthesized by a chemical vapor deposition?CVD?method using ZnS and ZnSe mixed power as the precursor.By changing the proportion of the reaction source to implement the regulation of nanowires ZnS_xSe_1-x band gap and by regulating the temperature and the pressure in the process of growth to ZnS_xSe_1-x one dimensional nanostructure morphology control,Optoelectronic properties were further studied by constructing photodetectors?PDs?.The main results are as follows:High-quality ZnS_xSe_1-x One-dimensional nanostructures were synthesized by a chemical vapor deposition?CVD?method,by regulating the temperature and the pressure in the process of growth to one dimensional nanostructure morphology control,And on this basis,by improving the way of implantation was prepared by different compositions of substrate ZnS_xSe_1-x nanostructures,realize to thecomponents of the control;Through the XRD,EDS analysis suggest that the alloyed nanostructures with modulated composition are successfully synthesized,and cover the full rang form ZnSe to ZnS.Take ZnS0.44Se0.56 for example,through the SEM,XPS,TEM analysis can be found that the NWs are clear and smooth with diameters and lengths of about 100 nm and several tens of micrometers,respectively.the NW is wurtzite hexagonal structure with [001] growth orientation with good uniformity,providing good material basis for preparation of photoelectric devices.Ternary nanowires for PL spectroscopy,ultraviolet-visible absorption spectrum and Raman spectrum analysis,the results showed that the preparation of the nanowires is a ternary alloy structure rather than a simple ZnSe and ZnS hybrid,administered analysis showed that the preparation of nanometer line of high quality,less defect,for the preparation of high quality photoelectric detector provides a good material basis.The photoresponse properties were investigated by fabricating ZnS0.44Se0.56 nanowires photoelectric detector,Ion/Ioff ratio can be obtained to be 8.1,when light illumination?410 nm?was turned on and off repeatedly,R and G are estimated to be1.5×106AW-1and 4.5×106,respectively,under light intensity of 0.3 mW cm-2,To further investigate the ability of the PD to follow a fast varying optical signal,the response speed was evaluated by modulating the incident light?410 nm,0.3 mW cm-2?with a mechanical chopper at 300 Hz,a fast response speed of 520 ?s /930 ?s was obtained,It is worth noting that the devices in this work show robust performances superior to the previous results.