The Preparation And Density Functional Theory Study Of InN Coating GaN Nanowires Composite Structure

Nanomaterials with composite tructures have recently become an increasingly important research and have wide use value because of its unique chemical and physical properties,following the semiconductor doping and the changes of morphology technologies.Gallium nitride(Ga N)and indium nitride(In N)belong to III-V family semiconductor materials,their nanowire structure have been successfully synthesized in the experiment,both two have the same hexagonal wurtzite structure and the similar crystal lattice parameters,which are sustained as theories for synthetising Ga N nanowires coated with In N.In this paper,we research the heterogeneous composite core-shell structure of In N coating Ga N nanowires in theoretical and experimental.Theoretically,the electronic structure and work function of Ga N nanowires coated with In N structure have been calculated via the density functional theory(DFT).The results indicate: In N coating Ga N nanowires,the electronic structure of Ga N nanowires is modified,the band gap is greatly decreased;the local electronic states near the conduction band minimum(CBM)are mainly introduced by In atoms,A large amount of local charge is distributed around In atoms at the core-shell interface,this is because the imbalance of carriers induces charge-transfer,and forms the space charge region.The work function of In N coating Ga N nanowires compared to pure Ga N nanowires is reduced.Experimently,our work was based on chemical vapor deposition(CVD),two-step growth method,Ga N(core)nanowires have been firstly synthesized using VLS mechanism,and In N coating Ga N nanowires were synthesized based on VS mechanism.In our experiment,the preperation of samples was choised from different In precursor and different coating temperature,respectively,and the samples were characterized by scanning electron microscope(SEM),X-ray diffraction(XRD)techniques and element energy spectrum analysis(EDS),the text results indicate:(1)The optimal In precursor is the mixture of In2O3 powder and In powder;(2)The optimum coating condition is 700 ?.