Preparation And Characterization Of Indium Gallium Nitrogen Nanomaterials By Halide Chemical Vapor Deposition

Indium nitride(InN)and indium gallium nitride(InGaN)are excellent semiconductor materials with broad application prospects.The band gap of InGaN can achieve continuous change between 0.7 e V of InN and 3.4 e V of GaN by adjusting the proportion of Inand Ga in the alloy composition,InGaN is widely used in solar cells,lasers,and detectors.The performance of InGaN materials determined by the crystal structure and composition is an important factor affecting the characteristics of electronic devices,but it has always been difficult to adjust the crystal structure and composition of InGaN materials.Therefore,the current mature preparation process is still dominated by the growth of InGaN with low in component,which seriously restricts the application of optoelectronic devices in different fields.This is due to the large difference between the atomic radius of Inand Ga,and the lattice mismatch between InN and GaN is up to about 10%.There is a large miscibility gap in thermodynamics,which leads to Insegregation and phase separation in InGaN,which affects the incorporation of in components.Halide vapor phase epitaxy(HCVD)is a method to prepare nitride semiconductors using group III halides with low sublimation temperature as the source material.This growth mode can theoretically reduce the miscible gap between Inn and Gan,and it is expected to achieve the preparation of high in component InGaN materials.However,there are not many reports about the preparation of InN-based materials by HCVD.Therefore,in this paper,the indium trichloride(InCl₃)and gallium trichloride(Ga Cl₃),which are easy to gasification,as reaction source to synthesize InN and InGaN nanomaterials on Si substrate by a self-made halide chemical vapor deposition(HCVD)device.The influence of growth process on the adjustment of crystal structure and composition of InN and InGaN was discussed.The specific research work and results are as follows:(1)The InN materials were synthesized on the Si(111)substrate by a self-made halide chemical vapor deposition(HCVD)device that expanded the blended growth area of reaction source.Indium chloride(InCl₃),which has a lower sublimation temperature,was used as the indium source.The effect of the growth temperature and NH₃flow on the structure and morphology of InN were discussed.The results show that:when the NH₃flow is unchanged,the crystal morphology of InN is transformed from a dispersed flaky morphology into an intertwined coral-like morphology by increasing the growth temperature,and the orientation of the(100)plane is enhanced.When the growth temperature keeps constant,the the crystal morphology of InN is transformed from a coral-like morphology into a vertical columnar morphology by increasing the ammonia gas flow,and the trend of crystal orientations changes from dominated non-polar(100)plane to overwhelming polar(002)plane.(2)On the basis of the growth of InN crystal,Ga Cl₃was added as gallium source,and the regulation of InGaN components under two kinds of transportation modes of?group source:single tube and double tube was discussed.The results show that when growing InGaN in a built-in single-tube transport III-group source,the content of the Ga source was changed.The Ga content in all samples was high,showing an amorphous film morphology and containing more Cl impurities.The addition of a small amount of H₂in the gas can eliminate Cl impurities;when InGaN is grown in a built-in double-tube transport group III source mode,the substrate was placed at the outlet of the Insource.Changing the amount of Ga source can adjust the InGaN composition The higher content of InGaN shows regular columnar morphology.