Synthesis And Luminescence Properties Of InGaN Nanometer Materials

Since ?-nitride semiconductors have excellent photoelectric properties,they have been developed as the most advanced semiconductor materials.In the recent years,the study of synthesis and properties of the In GaN ternary nanostructures has attracted much attention.InGaN materials have a variable band gap from 0.7 to 3.4 eV that covers nearly the whole solar spectrum.It was viewed as an ideal candidate full spectrum PV material.Concurrently,recent studies have found that InGaN material posses the property of absorption of light which split water and generate hydrogen.As a consequence,InGaN materials have important application value in new energy field.In this thesis,we synthesized GaN,InN and InGaN nanostructure on quartz and Si substrate using a home-made plasma enhanced chemical vapor deposition method.The structure,morphology and optical property of InN and InGaN material were also investigated.The results of the study are as follows:1.When the reaction chamber pressure is not the same,the PECVD system has a low pressure and high pressure operation modes.Considering the relationship between reactive nitrogen and metal vapor pressure,the experimental parameters are determined.When the reaction chamber pressure is 10 Pa-20 Pa,the evaporation temperature of In metal is 850?,the evaporation temperature of Ga metal is 950?,the angel of the evaporation furnace is 60 degrees,the distance between the substrate stage and PE electrode is 4 cm,the evaporation film was the best.The In film and GaN materials were also successfully prepared.2.A variety of morphologies of InN nanostructures were successfully prepared on quartz and silicon substrates.XRD shows that with the increase of substrate temperature and reaction time,the intensity of the diffraction peak becomes more obvious and its full width at half maximum becomes smaller.SEM shows that when the Si substrate temperature is 550?,the size of InN nanostructures become bigger.Raman shows that with the increase of substrate temperature,the scattering peak shifted to the high wave number and its full width at half maximum becomes wider.Compared to InN materials grown on quartz substrate,the Raman peak of InN materials grown on silicon substrate moved to low wave numbers.Infrared transmittance declined at around 1700 nm.With the substrate temperature increase,infrared transmittance decrease obviously.3.InGaN nanostructures were successfully synthesized on quartz and silicon substrates.SEM shows that with the increase of substrate temperature,the size of InN nanostructures become bigger.The growth process of InGaN was explained by using the Bedair model.In the Raman spectrum,E2(high)and A1(LO)modes were obviously observed.PL shows that with the increase of substrate temperature,the emission peaks shifted to the blue.With the growth time becomes longer,the emission peak shifted to the red.When substrate temperature was 650?,two emission peaks appear at the same time.The shift of the emission peak can be attributed to some defects in the InGaN material and non-uniform In component by the indium phase separation.