Tseng Yi-Chuan, Chang Sih-Wei, Lee Yang-Chun, Chen Hsuen-Li
Department of Materials Science and Engineering, National Taiwan University, No.1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan.
Center of Atomic Initiative for New Materials, National Taiwan University, No.1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan.
Nanophotonics. 2022 Jul 14;11(16):3583-3593. doi: 10.1515/nanoph-2022-0206. eCollection 2022 Sep.
In this paper, we demonstrate the first example of phonon-assisted hot luminescence (PAHL) emission from silicon (Si) spheres (diameter > 100nm) without using the plasmonic effect or quantum confinement effect. Instead, we excite the hot luminescence of Si by a strong thin-film-cavity-enhanced magnetic dipole resonance. The thin-film cavity (80 nm SiO/Ag) shows a strong co-enhancement with the magnetic dipole resonance of Si sphere (diameter = 120 nm). The concentrated electromagnetic fields induce significant light-matter interaction. Our Si sphere coupled with a thin-film cavity achieves a 10-fold field enhancement relative to the Si sphere without an enhancement substrate. Furthermore, we experimentally use cavity-enhanced magnetic dipole resonance to a 50-fold enhancement in PAHL. The measured internal quantum efficiency for the visible light emitted from the Si spheres was approximately 2.4%. Furthermore, we demonstrate the tunability of emission peaks merely by adjusting the sizes of Si spheres using thermal oxidation and etching processes. For comparison, we calculated the peak wavelength ( ) sensitivities (Δ /ΔDiameter) of Si spheres and Si QDs through Mie theory and effective mass approximation, respectively. The predicated peak sensitivities of the Si spheres ranged from 1.3 to 3.2; they were much more controllable than those of the Si QDs (200-400). Thus, the peak wavelengths of the PAHL of the Si spheres could be modulated and controlled much more precisely and readily than that of the Si QDs. With the tunability and strong electromagnetic field confinement, the cavity-enhanced magnetic dipole resonance appears to have great potential in the development of all-optical processing based on Si photonics.
在本文中，我们展示了首例在不使用等离子体效应或量子限制效应的情况下，从硅（Si）球体（直径>100nm）发出的声子辅助热发光（PAHL）。相反，我们通过强薄膜腔增强磁偶极子共振来激发Si的热发光。薄膜腔（80nm SiO/Ag）与Si球体（直径 = 120nm）的磁偶极子共振表现出强烈的协同增强。集中的电磁场引发了显著的光与物质相互作用。与没有增强衬底的Si球体相比，我们的Si球体与薄膜腔耦合实现了10倍的场增强。此外，我们通过实验利用腔增强磁偶极子共振将PAHL提高了50倍。从Si球体发射的可见光的测量内量子效率约为2.4%。此外，我们仅通过使用热氧化和蚀刻工艺调整Si球体的尺寸，就证明了发射峰的可调谐性。为了进行比较，我们分别通过米氏理论和有效质量近似计算了Si球体和Si量子点的峰值波长（ ）灵敏度（Δ /Δ直径）。Si球体预测的峰值灵敏度范围为1.3至3.2；它们比Si量子点（200 - 400）的灵敏度更易于控制。因此，Si球体PAHL的峰值波长比Si量子点的峰值波长能够更精确且更容易地进行调制和控制。凭借可调谐性和强电磁场限制，腔增强磁偶极子共振在基于Si光子学的全光处理发展中似乎具有巨大潜力。
