Preparation Of Antimony-based Compound Semiconductor Nanowires And Research On Its Photodetectors

Indium antimonide?In Sb?and gallium antimonide?Ga Sb?are important narrow band gap materials in ?-? semiconductors.In Sb has the highest electron mobility(78000 cm²v^?1s^?1)and gallium antimonide has the highest hole mobility(850 cm²v^?1s^?1),so that In Sb and Ga Sb as well as their ternary compound indium gallium antimony?In Ga Sb?were widely used to make high?speed devices and infrared?IR?detectors.In addition,antimony sulfide?Sb₂S₃?in the V?VI group has good photosensitive and thermoelectric properties,and these antimony?based semiconductors have attracted scholars' interest.In this thesis,we have studied the preparation of indium gallium antimony nanowires and antimony sulfide nanowires.Nanostructured photodetectors were fabricated using In Ga Sb/Sb₂S₃ nanowires as active regions and Ag nanowires or MXenes as electrodes.The main work is as follows:1.Au thin films were deposited on silicon substrates by magnetron sputtering and annealed in furnace at 700? for 15 min.After annealing,Au thin films on the substrates will be transformed into Au nanoparticles.Indium gallium antimony nanowires were prepared by vapor phase transfer using Au nanoparticles as catalyst,In Sb powder and Ga Sb powder as source materials,and characterized by electron microscopy?SEM and TEM?and X?ray Diffraction?XRD?.Ultra?long silver nanowires were fabricated with ethylene glycol and PVP.Photodetectors were fabricated using In Ga Sb nanowires as active region and Ag nanowires as electrodes,and their performances were tested.We found that the I?V characteristic curve was asymmetric,which was consistent with the relevant reports.The author think that the asymmetric phenomenon is mainly caused by the different contact area between the semiconductor nanowires and the electrodes on both sides.Because the oxygen in the air will adsorb on the interface and capture electrons,the thickness of the depletion layer will increase.The different contact area will lead to the different thickness increase,showing the potential barriers of different sizes at both ends,resulting in the asymmetric phenomenon.2.Antimony sulfide nanowires were prepared by hydrothermal method.We found that the average length and uniformity of antimony sulfide nanowires were improved by adding PVP in the preparation process.We think that the morphology of nanowires is related to PVP and EG which was used as solvents.PVP is helpful to the anisotropy of growth and tends to produce one-dimensional materials,but PVP also tends to agglomerate nanowires,and EG can prevent agglomerations to a certain extent and help the dispersion of nanowires.Then,antimony sulfide nanowires were used as active regions,silver nanowires and Ti₃C₂ as electrodes to prepare photodetectors,and the performance of the devices was tested.We find that Ti₃C₂ can improve the sensitivity and response speed of the device.We think it was caused by Ti₃C₂ accelerating the hole migration of the whole device.When silver nanowire was used as the electrode at one end of the device and Ti₃C₂ was used as the electrode at another end,the device shows self-driving characteristics.The author speculates that the hole can not be rapidly compounded at the interface of silver nanowire / antimony sulfide nanowire which lead to asymmetric hole migration.