1.55μm通信波段InAs/GaAs量子点制备方法研究

Preparation Method of InAs/GaAs Quantum Dots for 1.55 μm Communication Band

利用分子束外延技术在GaAs衬底上生长InAs量子点,采用梯度生长法实现了量子点的成岛参数和量子点密度精确可控。通过在GaAs衬底上生长InGaAs组分渐变缓冲层进而自组织外延InAs量子点的方法,将GaAs衬底的InAs量子点发光波长拓展到了1550nm通讯波段,并研究了渐变层中最大In组分、以及InAs淀积量等因素对于量子点发光性能的影响。结果显示,渐变层最上层In组分越大,与InAs量子点的失配越小生长尺寸越大,量子点的发光波长越长,光致荧光谱呈现整体红移的趋势。在渐变缓冲层上外延InAs的淀积量为1.65ML时可以得到线宽较窄强度较高的单量子点发光峰。

InAs quantum dots are grown on a GaAs substrate by MBE(molecular beam epitaxy).Gradient growth method is adopted to realize accurate control of islanding parameters and density of quantum dots.By growing the InGaAs metamorphic buffer layer on GaAs substrate and self-organizing epitaxial InAs quantum dots,the GaAs-based InAs quantum dot emission wavelength is extended to 1 550 nm communication band.The effects of the maximum In composition and the deposition amount of InAs on the luminescence properties of quantum dots are explored.The experiment results indicate that the larger the In component in the uppermost layer of the gradient layer,the smaller the mismatch between the InAs quantum dots and the larger the growth size,the longer the luminescence wavelength of the quantum dots,and the photoluminescence spectrum shows a trend of overall red shift.When the deposition amount of InAs on the tapered buffer layer is 1.65 ML,the single quantum dot emission peak with narrower linewidth and higher intensity can be obtained.