We report on MoSi-based superconducting nanowire single-photon detectors on a gallium arsenide substrate. MoSi deposited on a passivated GaAs surface has the same critical temperature as MoSi deposited on silicon. The critical temperature decreases slightly on depositing MoSi directly on the native oxide of GaAs. Hence, MoSi works well as a thin-film superconductor on GaAs. We propose that the amorphous structure of MoSi ensures compatibility with the GaAs matrix. Superconducting nanowire single-photon detectors (SNSPDs) are fabricated with MoSi on GaAs using a meander-wire design. The SNSPD metrics are very similar to those of devices fabricated with the same procedure on a silicon substrate. We observe a plateau in the response-versus-bias curve signalling a saturated internal quantum efficiency. The plateau remains even at an elevated temperature, 2.2 K, at a wavelength of 980 nm. We achieve a timing jitter of 50 ps and a recovery time of 29 ns. These results point to the promise of integrating MoSi SNSPDs with GaAs photonic circuits.
High-Responsivity Photodetection by Self-Catalyzed Phase-Pure P-GaAs Nanowire
缺陷对于光电子器件是有害的，例如堆垛层错可以形成载流子传输势垒，并且具有深能级的外来杂质（Au）可以形成载流子陷阱和非辐射复合中心。本文首先研制了具有纯锌层（ZB）结构的自催化p型GaAs纳米线（NWs），并以此制作了光电探测器。由于不存在堆垛层错并抑制了大量深能级缺陷，该光电探测器在室温下具有1.45 x 105 A W^-1的高光响应度，对波长为632.8 nm的低强度光信号具有高达1.48 x 10^14琼斯的优异比探测率（D*），优于先前报道的NW基光电探测器。这些结果表明，这些自催化纯ZB GaAs纳米线是光电子应用的有前途的候选人。
Strain distribution in zincblende and wurtzite GaAs nanowires bent by a one-sided (In, Al)As stressor shell: consequences for torsion, chirality, and piezoelectricity
Carrier Recombination in Highly Uniform and Phase-Pure GaAs/(Al,Ga)As Core/Shell Nanowire Arrays on Si(111): Mott Transition and Internal Quantum Efficiency
Monolithic axial InGaAs quantum dot emitters in GaAs-based nanowires via Sb-mediated facet engineering
Walter Schottky Institute, TUM School of Natural Sciences, Technical University of Munich（慕尼黑工业大学沃尔特·施科特基研究所自然科学学院）；Institute for Physics and Astronomy, Technical University Berlin（柏林工业大学物理与天文学研究所）；Department of Chemistry, Ludwig-Maximilians-University of Munich（慕尼黑大学化学系）；Walter Schottky Institute, TUM School of Computation, Information and Technology, Technical University of Munich（慕尼黑工业大学沃尔特·施科特基研究所计算、信息与技术学院）；Department of Physics, University of California, Berkeley（加州大学伯克利分校物理系）
Spatially-resolved luminescence and crystal structure of single core-shell nanowires measured in the as-grown geometry
我们报道了单个的、生长态的核-多壳GaAs/In $_{0.15}$ Ga $_{0.85}$ As/GaAs/AlAs/GaAs纳米线的结构和光学性质之间的直接相关性。通过分子束外延在预先图案化的Si（111）衬底上制造，在一排良好分离的成核位置上，可以在生长的几何形状中访问单个纳米线。通过同步辐射纳米探针X射线衍射技术监测轴向111布拉格反射，揭示了沿纳米线生长轴的多型体分布。对于相同的纳米线，空间分辨的发射特性，通过阴极发光高光谱线扫描在扫描电子显微镜。相关的两个测量，我们揭示了一个蓝移的壳量子阱发射能量结合的发射强度增加的片段表现出的混合结构的交替纤锌矿和锌的堆叠相比，纯晶体多型体。这种混合结构的存在下，独立地证实了横截面透射电子显微镜。
