Structural properties of InxGa_(1−x)N/GaN multi-quantum wells(MQWs)grown on sapphire by metal organic chemical vapor deposition are investigated by synchrotron radiation x-ray diffraction(SRXRD),Rutherford backscatter...Structural properties of InxGa_(1−x)N/GaN multi-quantum wells(MQWs)grown on sapphire by metal organic chemical vapor deposition are investigated by synchrotron radiation x-ray diffraction(SRXRD),Rutherford backscattering/channelling(RBS/C)and high-resolution transmission electron microscopy.The sample consists of eight periods of InxGa_(1−x)N/GaN wells of 2.1 nm thickness and 8.5 nm thickness of GaN barrier,and the results are very close,which verifies the accuracy of the three methods.The indium content in InxGa_(1−x)N/GaN MQWs by SRXRD and RBS/C is estimated,and results are in general the same.By RBS/C random spectra,the indium atomic lattice substitution rate is 94.0%,indicating that almost all indium atoms in InxGa_(1−x)N/GaN MQWs are at substitution,that the indium distribution of each layer in InxGa_(1−x)N/GaN MQWs is very homogeneous and that the InxGa_(1−x)N/GaN MQWs have a very good crystalline quality.It is not accurate to estimate indium content in InxGa_(1−x)N/GaN MQWs by photoluminescence(PL)spectra,because the result from the PL experimental method is very different from the results by the SRXRD and RBS/C experimental methods.展开更多
基金by the National Natural Science Foundation of China under Grant No 10875004 and 11005005the National Basic Research Program of China under Grant No 2010CB832904.
文摘Structural properties of InxGa_(1−x)N/GaN multi-quantum wells(MQWs)grown on sapphire by metal organic chemical vapor deposition are investigated by synchrotron radiation x-ray diffraction(SRXRD),Rutherford backscattering/channelling(RBS/C)and high-resolution transmission electron microscopy.The sample consists of eight periods of InxGa_(1−x)N/GaN wells of 2.1 nm thickness and 8.5 nm thickness of GaN barrier,and the results are very close,which verifies the accuracy of the three methods.The indium content in InxGa_(1−x)N/GaN MQWs by SRXRD and RBS/C is estimated,and results are in general the same.By RBS/C random spectra,the indium atomic lattice substitution rate is 94.0%,indicating that almost all indium atoms in InxGa_(1−x)N/GaN MQWs are at substitution,that the indium distribution of each layer in InxGa_(1−x)N/GaN MQWs is very homogeneous and that the InxGa_(1−x)N/GaN MQWs have a very good crystalline quality.It is not accurate to estimate indium content in InxGa_(1−x)N/GaN MQWs by photoluminescence(PL)spectra,because the result from the PL experimental method is very different from the results by the SRXRD and RBS/C experimental methods.
