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 SiO2/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 (λ peak) sensitivities (Δλ peak/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.

中文翻译：

---

腔增强磁偶极子共振诱导百纳米大小硅球的热发光

在本文中，我们展示了第一个不使用等离子体效应或量子限制效应的硅 (Si) 球体（直径 > 100nm）发射声子辅助热发光 (PAHL) 的例子。相反，我们通过强薄膜腔增强磁偶极子共振激发 Si 的热发光。薄膜腔（80 nm SiO2/Ag) 与 Si 球的磁偶极子共振（直径 = 120 nm）显示出强烈的共同增强。集中的电磁场会引起显着的光物质相互作用。我们的硅球与薄膜腔相结合，相对于没有增强衬底的硅球实现了 10 倍的场增强。此外，我们实验性地使用腔增强磁偶极子共振使 PAHL 增强 50 倍。从 Si 球发出的可见光的测量内部量子效率约为 2.4%。此外，我们仅通过使用热氧化和蚀刻工艺调整硅球的尺寸来证明发射峰的可调性。为了比较，我们计算了峰值波长（λ 顶峰) 灵敏度 (Δλ 顶峰/ΔDiameter）分别通过 Mie 理论和有效质量近似得到 Si 球和 Si QD。Si 球的预测峰灵敏度范围为 1.3 至 3.2；它们比 Si QD (200-400) 更可控。因此，Si 球的 PAHL 的峰值波长可以比 Si QD 更精确和更容易地调制和控制。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硅光子学的全光处理方面具有巨大的发展潜力。