Institute for Nanoscience and Engineering, University of Arkansas, 731 W Dickson Street, Fayetteville, AR 72701, USA.
Nanotechnology. 2014 Jan 24;25(3):035702. doi: 10.1088/0957-4484/25/3/035702. Epub 2013 Dec 17.
The structural and optical properties of GaAs1-xBix quantum wells (QWs) symmetrically clad by GaAs barriers with and without additional confining AlGaAs layers are studied. It is shown that a GaAs/GaAs1-xBix/GaAs QW with x ~ 4% and well width of ~ 4 nm grown by molecular beam epitaxy demonstrates efficient photoluminescence (PL) that becomes significantly more thermally stable when a cladding AlGaAs layer is added to the QW structure. The PL behavior for temperatures between 10 and 300 K and for excitation intensities varying by seven orders of magnitude can be well described in terms of the dynamics of excitons including carrier capture in the QW layer, thermal emission and diffusion into the cladding barriers. Understanding the role of these processes in the luminescence of dilute GaAs1-xBix QW structures facilitates the creation of highly efficient devices with reduced thermal sensitivity and low threshold current.
砷化镓 (GaAs)1-x 铟 (Bi) 量子阱 (QW) 的结构和光学性质，其被具有和不具有附加限制的 AlGaAs 层的 GaAs 势垒对称地覆盖。研究表明，通过分子束外延生长的具有约 4%的 x 值和约 4nm 阱宽的 GaAs/GaAs1-xBix/GaAs QW 在添加到 QW 结构的覆盖 AlGaAs 层时表现出有效的光致发光 (PL)，其显著更热稳定。在 10 到 300K 的温度范围内以及激发强度变化七个数量级的情况下，PL 行为可以很好地用包括激子动力学的载流子俘获、热发射和扩散到覆盖势垒的载流子来描述。了解这些过程在稀 GaAs1-xBix QW 结构中的发光中的作用有助于创建具有降低的热灵敏度和低阈值电流的高效器件。
