Abstract: InGaN/GaN MQWs were grown on sapphire(Al2O3) substrates by Metal-Organic Chemical Vapor Deposition(MOCVD).The influence of TMIn flow on the alloy content, crystal quality and optical properties of InGaN/GaN MQWs were investigated by adjusting the TMIn flow in epitaxial growth process.Structural and optical properties of MQWs were characterized by high-resolution X-ray diffraction (HRXRD), atomic force microscopy (AFM) and photoluminescence (PL).HRXRD shows that with the increase of TMIn flow, the angle between the "0" peak and the GaN peak deviates from each other, and more In is incorporated into the film.HRXRD and AFM shows that with the increasing of TMIn flow, the density of dislocation and V-pits increases, and the crystal quality severely deteriorate.It is also found that the weaker PL intensity and larger FWHM value are presented with increasing TMIn fiow, which could be attributed to the deterioration of the crystal quality confirmed by HRXRD and AFM results.Thus, the structual and optical properties of InGaN/GaN MQWs are strongly affected by the TMIn flow.

Key words: InGaN/GaN MQWs were grown on sapphire(Al2O3) substrates by Metal-Organic Chemical Vapor Deposition(MOCVD).The influence of TMIn flow on the alloy content, crystal quality and optical properties of InGaN/GaN MQWs were investigated by adjusting the TMIn flow in epitaxial growth process.Structural and optical properties of MQWs were characterized by high-resolution X-ray diffraction (HRXRD), atomic force microscopy (AFM) and photoluminescence (PL).HRXRD shows that with the increase of TMIn flow, the angle between the "0" peak and the GaN peak deviates from each other, and more In is incorporated into the film.HRXRD and AFM shows that with the increasing of TMIn flow, the density of dislocation and V-pits increases, and the crystal quality severely deteriorate.It is also found that the weaker PL intensity and larger FWHM value are presented with increasing TMIn fiow, which could be attributed to the deterioration of the crystal quality confirmed by HRXRD and AFM results.Thus, the structual and optical properties of InGaN/GaN MQWs are strongly affected by the TMIn flow.