The Synthesis And Physical Propetries Studies Of One-Dimensional Indium Nitride Semiconductor Nanomaterials

According to a great quantity of literatures, it is proved that the band gap of InNmay be about0.7eV recently, rather than the previously generally accepted1.9eV. Theemission wavelength of InN achieves1.55μm with the decrease of band gap.Therefore, we can obtain continuous and adjustable direct band gap from0.7eV（InN）to3.4eV（GaN） by adjusting the change of In component x in ternary alloy InxGa1-xN,which provides almost perfect corresponding and matching energy gap correspondingto the solar spectrum, making the design of new-style and high-efficiency solar cellsto be a significant possibility. Theoretically, the photoelectric conversion efficiency ofsolar cells based on InN could be close to the theoretical limit of solar cells（72%）. Thetheoretical research demonstrates that InN possesses good steady state and transientelectrical transmission characteristics, and other excellent properties, such as themaximal electron mobility, the maximal peak rate, the maximal saturated electrondrift rate, the maximal spike rate, the minimal band gap, the minimal electroneffective mass and so on in all Ⅲ nitride semiconductor materials.The excellent properties and potential application value of InN arouse greatinterest and extensive attention among the scientists, making some significantbreakthrough in the past, however, both the synthesis and test of InN are very difficult:①InN of poor thermal stability needs upper N balance pressure, but NH3as nitrogensource has upper decomposition temperature, which is a pair of contradiction in InNgrowth.②It is difficult to find suitable substrate that match the lattice constant andthermal expansion coefficient of InN.③Synthesized intrinsic InN always revealsstrong n type conductivity characteristics, which brings great challenge to p typedoping. Due to above these difficulties, up to now, the research and understanding of synthesis and thermal, optical and electrical properties of InN is not a quarter asdeeply and thoroughly as other Ⅲ nitride semiconductor materials.Based on the above discussion and analysis, we propose a complete set ofsystematic solutions to the problems and research ideas:Firstly, we synthesize indium nitride（InN） semiconductor nanomaterialssuccessfully, taking metal indium particles（In） and ammonia（NH3） as initial rawmaterials, taking common quartz boat as carrier, without any catalyst, using the tubefurnace as the basic synthesis instrument, applying chemical vaportransportation（CVT） principle, via vapor solid（VS） growth mechanism. Then, wecontrol the reaction conditions, such as reaction temperature, gas flow, reaction timeand so on, in order to achieve the purpose of adjusting morphology of InN. At last, weachieve nanostructures of InN of abundant and peculiar morphology, such asnanowires（some nanowires possess branch structure）, nanorods, nanotubes, nanowiresentanglements, hollow nanotubes, nanotube slots, nano sugar-coated haws（nanotubesgrow on the nanowire at intervals） and so on. In addition, we characterize structure,bond, morphology and composition of synthesized InN by various methods, such asX-ray diffraction（XRD）, X-ray photoelectron spectroscopy（XPS）, scanning electronmicroscopy（SEM）, high resolution scanning electron microscopy（HR-SEM）, highresolution transmission electron microscopy（HR-TEM） and so on and discover thatInN is pure single phase hexagonal wurtzite structure.Secondly, we synthesize indium oxide（In₂O₃） semiconductor nanomaterials byoxidizing synthesized InN in the air successfully. In addition, we discover that In₂O₃is pure single phase body-centered cubic crystal structure and In₂O₃and InN possessthe same morphology, namely, the morphology of InN remains unchanged when it isoxidized in the air, which provides a new road for the synthesis of In₂O₃of pure singlephase body-centered cubic crystal structure.Thirdly, we research the physical properties of InN and In₂O₃and the opticalproperties are prime research objects. In addition, we characterize synthesized InNand In₂O₃by various methods, such as fourier transform infrared spectroscopy（FTIR）,ultraviolet visible absorption spectroscopy（UV-VIS）, fluorescence spectroscopy（FS）, raman spectroscopy（RS） and so on.Fourthly, we research phase transition under high pressure of synthesized InN byin situ high pressure synchrotron radiation angular dispersion X-ray diffraction inbrookhaven national laboratory of America. When the pressure is about12.91GPa,InN begins to transform of structure phase and transform from InN of hexagonalwurtzite structure to InN of cubic rocksalt structure at last.