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在GaSb衬底上用LPE法生长了晶格匹配的AlGaAsSb外延层。用室温光致发光和X射线双晶衍射分别测量了材料的禁带宽度和晶格常数,并与用内插法计算的结果进行了比较。用C-V和van der Pauw法测量了样品的电学参数。用激光喇曼散射和低温光致发光研究了材料的光学性质,观察到了类GaSb的LO模和类AlSb的LO模以及LO声子与等离子激元的耦合模L_-;对x=0.2,y=0.025的样品,由低温到室温的变温光致发光测量确定的禁带宽度的温度系数为-3.2×10~(-4)eV/K。此外对于晶格失配,P型的原因以及PL谱峰的展宽等问题进行了讨论。
A lattice-matched AlGaAsSb epitaxial layer was grown by LPE on a GaSb substrate. The forbidden band width and the lattice constant of the material were measured respectively by room temperature photoluminescence and X-ray double crystal diffraction. The results were compared with those obtained by interpolation. The electrical parameters of the samples were measured by the C-V and van der Pauw methods. The optical properties of the materials were investigated by laser Raman scattering and low-temperature photoluminescence. The LO modes of the GaSb-like and AlSb-like LO modes and the coupled mode L_- of the LO phonon and plasmon were observed. For x = 0.2, y = 0.025, the temperature coefficient of the forbidden band width determined by the variable temperature photoluminescence measurement from low temperature to room temperature is -3.2 × 10 -4 eV / K. In addition, the issues of lattice mismatch, P type and broadening of PL spectrum are discussed.