Scaparra Bianca, Sirotti Elise, Ajay Akhil, Jonas Björn, Costa Beatrice, Riedl Hubert, Avdienko Pavel, Sharp Ian D, Koblmüller Gregor, Zallo Eugenio, Finley Jonathan J, Müller Kai
Walter Schottky Institut, Technical University of Munich, Garching 85748, Germany.
TUM School of School of Computation, Information and Technology, Department of Electrical Engineering, Technical University of Munich, Garching 85748, Germany.
ACS Appl Nano Mater. 2024 Nov 20;7(23):26854-26862. doi: 10.1021/acsanm.4c04810. eCollection 2024 Dec 13.
InAs semiconductor quantum dots (QDs) emitting in the near-infrared are promising platforms for on-demand single-photon sources and spin-photon interfaces. However, the realization of quantum-photonic nanodevices emitting in the telecom windows with similar performance remains an open challenge. In particular, nanophotonic devices incorporating quantum light emitting diodes in the telecom C-band based on GaAs substrates are still lacking due to the relaxation of the lattice constant along the InGaAs graded layer which makes the implementation of electrically contacted devices challenging. Here, we report an optimized heterostructure design for QDs emitting in the telecom O- and C-bands grown by means of molecular beam epitaxy. The InAs QDs are embedded in mostly relaxed InGaAs matrices with fixed indium content grown on top of compositionally graded InGaAs buffers. Reciprocal space maps of the indium profiles and optical absorption spectra are used to optimize InGaAs and InGaAs matrices, accounting for the chosen indium grading profile. This approach results in a tunable QD photoluminescence (PL) emission from 1200 up to 1600 nm. Power and polarization dependent micro-PL measurements performed at 4 K reveal exciton-biexciton complexes from quantum dots emitting in the telecom O- and C-bands. The presented study establishes a flexible platform that can be an essential component for advanced photonic devices based on InAs/GaAs that serve as building blocks for future quantum networks.
发射近红外光的砷化铟半导体量子点是按需单光子源和自旋光子界面的有前景的平台。然而，实现具有类似性能且在电信窗口发射的量子光子纳米器件仍然是一个悬而未决的挑战。特别是，基于砷化镓衬底的电信C波段中包含量子发光二极管的纳米光子器件仍然缺乏，这是由于沿铟镓砷渐变层的晶格常数弛豫，使得实现电接触器件具有挑战性。在此，我们报告了一种通过分子束外延生长的、用于在电信O波段和C波段发射的量子点的优化异质结构设计。砷化铟量子点嵌入在成分渐变的铟镓砷缓冲层顶部生长的、铟含量固定的大部分弛豫的铟镓砷基质中。铟分布的倒易空间图和光吸收光谱用于优化铟镓砷和铟镓砷基质，同时考虑所选的铟渐变分布。这种方法导致量子点的光致发光（PL）发射在1200至1600纳米范围内可调谐。在4K下进行的功率和偏振相关的显微PL测量揭示了在电信O波段和C波段发射的量子点中的激子 - 双激子复合体。所呈现的研究建立了一个灵活的平台，该平台可以是基于砷化铟/砷化镓的先进光子器件的重要组成部分，这些器件将作为未来量子网络的构建模块。
