Kersting Elias, Babin Hans-Georg, Spitzer Nikolai, Yan Jun-Yong, Liu Feng, Wieck Andreas D, Ludwig Arne
Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Universitätsstraße 150, 44801 Bochum, Germany.
State Key Laboratory of Extreme Photonics and Instrumentation, College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou 310027, China.
Nanomaterials (Basel). 2025 Jan 21;15(3):157. doi: 10.3390/nano15030157.
Quantum dot (QD)-based single-photon emitter devices today are based on self-assembled random position nucleated QDs emitting at random wavelengths. Deterministic QD growth in position and emitter wavelength would be highly appreciated for industry-scale high-yield device manufacturing from wafers. Local droplet etching during molecular beam epitaxy is an all in situ method that allows excellent density control and predetermines the nucleation site of quantum dots. This method can produce strain-free GaAs QDs with excellent photonic and spin properties. Here, we focus on the emitter wavelength homogeneity. By wafer rotation-synchronized shutter opening time and adapted growth parameters, we grow QDs with a narrow peak emission wavelength homogeneity with no more than 1.2 nm shifts on a 45 mm diameter area and a narrow inhomogeneous ensemble broadening of only 2 nm at 4 K. The emission wavelength of these strain-free GaAs QDs is <800 nm, attractive for quantum optics experiments and quantum memory applications. We can use a similar random local droplet nucleation, nanohole drilling, and now, InAs infilling to produce QDs emitting in the telecommunication optical fiber transparency window around 1.3 µm, the so-called O-band. For this approach, we demonstrate good wavelength homogeneity and excellent density homogeneity beyond the possibilities of standard Stranski-Krastanov self-assembly. We discuss our methodology, structural and optical properties, and limitations set by our current setup capabilities.
如今，基于量子点（QD）的单光子发射器件是基于自组装的随机位置成核量子点，其发射波长随机。对于从晶圆进行工业规模的高产量器件制造而言，量子点在位置和发射波长上的确定性生长将非常受欢迎。分子束外延过程中的局部液滴蚀刻是一种全原位方法，它能够实现出色的密度控制，并预先确定量子点的成核位置。这种方法可以生产出具有优异光子和自旋特性的无应变砷化镓量子点。在此，我们关注发射波长的均匀性。通过晶圆旋转同步快门开启时间和调整生长参数，我们生长出的量子点具有窄的峰值发射波长均匀性，在直径45毫米的区域内波长偏移不超过1.2纳米，并且在4K温度下非均匀展宽仅为2纳米。这些无应变砷化镓量子点的发射波长小于800纳米，对量子光学实验和量子存储应用具有吸引力。我们可以使用类似的随机局部液滴成核、纳米孔钻孔，以及现在的铟砷填充方法来制备在电信光纤透明窗口约1.3微米（即所谓的O波段）发射的量子点。对于这种方法，我们展示了良好的波长均匀性和出色的密度均匀性，这超出了标准斯特兰斯基 - 克拉斯坦诺夫自组装的能力范围。我们讨论了我们的方法、结构和光学性质，以及当前设置能力所带来的局限性。
