研究了生长在GaN/Al2O3模板层上的InGaN合金的微结构形态,并通过Raman光谱测定了InGaN合金的晶相,采用分光镜椭圆测量对InGaN合金的光学带隙进行了研究,分析了InGaN合金带隙产生Stokes偏移的本质及原因.AFM显微图表明生长在GaN/Al2O3模板层上的InGaN合金的微结构晶体质量得到了很好的改善.In-CaN合金的Raman光谱曲线非常微弱,与GaN/Al2O3的Raman光谱曲线几乎完全重叠.通过分光镜椭圆测量可知,InGaN合金的光学带隙Eg随着In含量的增加而减少.InGaN合金在红外区域表现出强烈的光致发光峰,随着Ga含量的增加,光致发光峰表现出较大的蓝移即Stokes偏移.在InGaN合金的中间In组分附近Stokes偏移达到最大值.产生Stokes偏移的主要原因是InN在GaN中具有较低的混溶性.Stokes偏移也可归结为InGaN合金中存在局域态,InGaN合金中栽流子的局域化程度越高,Stokes偏移就越大.
参考文献
| [1] | Vurgaftman I;Meyer J R .Band parameter of nitrogen-containing semiconductors[J].Journal of Applied Physics,2003,94:3675. |
| [2] | Mukai T;Nagahama S;Kozaki T;Sano M;Morita D;Yanamoto T;Yamamoto M;Akashi K;Masui S .Current status and future prospects of GaN-based LEDs and LDs[J].Physica Status Solidi, A. Applied Research,2004(12):2712-2716. |
| [3] | Wu J;Walukiewicz W;Yu K M et al.Superior radiation resistance of In1-xGax N alloys:A full-solar-spectrum photovoltaic material,system[J].Journal of Applied Physics,2003,94:6477. |
| [4] | Leung MMY.;Li EH.;Djurisic AB. .Refractive index of InGaN/GaN quantum well[J].Journal of Applied Physics,1998(11):6312-6317. |
| [5] | Yamaguchi M. .III-V compound multi-junction solar cells: present and future[J].Solar Energy Materials and Solar Cells: An International Journal Devoted to Photovoltaic, Photothermal, and Photochemical Solar Energy Conversion,2003(1/2):261-269. |
| [6] | Rao M;Kim D;Mahajan S .Compositional dependence of phase separation in InGaN layers[J].Applied physics letters,2004(11):1961-1963. |
| [7] | Tripathy S;Chua S J;Chen P et al.Micro-Raman investigation of strain in GaN and AlxGa1-x N/GaN heterostructures grown on Si(111)[J].Journal of Applied Physics,2002,92:3503. |
| [8] | Brockt G;Lakner H .Probing the local dielectric/optical properties of group Ⅲ-Nitrides by spatially resolved EELS on the nanometer scale[J].Materials Science and Engineering B,1999,59:155. |
| [9] | Siegle H.;Filippidis L.;Litvinchuk AP.;Hoffmann A. Thomsen C.;Kaczmarczyk G. .ZONE-BOUNDARY PHONONS IN HEXAGONAL AND CUBIC GAN[J].Physical Review.B.Condensed Matter,1997(11):7000-7004. |
| [10] | Huang J H;Hsieh K Y;Tsai J K et al.Indium-facilitated growth and characterization of N-polar GaN by RF plasmaassisted molecular beam epitaxy[J].Journal of Crystal Growth,2004,263:301. |
| [11] | McCluskey MD.;Master CP.;Romano LT.;Johnson NM.;Van de Walle CG. .Large band gap bowing of InxGa1-xN alloys[J].Applied physics letters,1998(21):2725-2726. |
| [12] | Lee MH.;Oh E.;Kim KJ. .Ellipsometric investigation of optical constant and band gap of Ga1-xInxN/GaN (x <= 0.12) heterostructures[J].Solid State Communications,2000(6):325-328. |
| [13] | Li SX;Haller EE;Yu KM;Walukiewicz W;Ager JW;Wu J;Shan W;Lu H;Schaff WJ .Effect of native defects on optical properties of InxGa1-xN alloys[J].Applied physics letters,2005(16):1905-1-1905-3-0. |
| [14] | Veal T D;Piper L F J;Phillips M R et al.Scanning tunneling spectroscopy of quantized electron accumulation at InxGa1-x N surfaces[J].Physical Status Solidi A,2006,203:85. |
| [15] | Davydov V Yu;Klochikhin A A;Emtsev V V et al.Band Gap of InN and In-Rich InxGa1-xN (0.36《x《1) alloys[J].Physical Status Solidi B Basic Research,2002,230:R4. |
| [16] | Ferhat M;Furthmuller J;Bechstedt F .Gap bowing and Stokes shift in InxGa1-x N alloys:First-principles studies[J].Applied Physics Letters,2002,80:1394. |
| [17] | Wu J;Walukiewicz W et al.Small band gap bowing in In1-xGax N alloys[J].Applied Physics Letters,2002,80:4741. |
| [18] | Kazlauskas K;Tamulaitis G;Pobedinskas P;Zukauskas A;Springis M;Huang CF;Cheng YC;Yang CC .Exciton hopping in InxGa1-xN multiple quantum wells[J].Physical review, B. Condensed matter and materials physics,2005(8):5306-1-5306-5-0. |
| [19] | Chichibu S;Azuhata T;Sota T et al.Spontaneous emission of localized excitons in InGaN single and multi-quantum well structures[J].Applied Physics Letters,1996,69:4188. |
| [20] | Chang H J;Chen C H;Chen Y F et al.Direct evidence of nanocluster-induced luminescence in InGaN epifilrns[J].Applied Physics Letters,2005,86:021911-0211-3. |
| [21] | Huang YH;Cheng CL;Chen TT;Chen YF;Tsen KT .Studies of stokes shift in InxGa1-xN alloys[J].Journal of Applied Physics,2007(10):3521-1-3521-4-0. |
上一张
下一张
上一张
下一张
计量
- 下载量()
- 访问量()
文章评分
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%