Speaker
Description
Silicon’s transparency in the telecommunication bands (1260–1625 nm) has traditionally required hybrid integration of materials such as germanium for photodetection, limiting scalability and CMOS compatibility [1-3]. Here, we present a strategy based on ion-beam engineering of deep-level dopants in silicon to realize all-silicon, waveguide-coupled photodetectors operating at room temperature in the telecom C band. By implanting deep-level dopants near the solid-solubility limit, sub-bandgap absorption is enhanced via defect-mediated states, while preserving electronic transport [4].
The resulting devices achieve a responsivity of 0.56 A/W, external quantum efficiency of 44.8%, a 2 GHz bandwidth, and a noise-equivalent power of 4.2×10-10 W/Hz1/2 at 1550 nm. These results demonstrate that ion implantation can create optically active defect states in silicon with practical photodetection performance, enabling monolithic integration into photonic circuits. Beyond device operation, this approach provides insight into the formation, energy levels, and transport properties of deep-level centers in silicon, highlighting the potential of ion-beam techniques for defect engineering and functionalization of silicon for advanced optoelectronic and quantum photonic applications.
[1] Shekhar, S. et al. Roadmapping the next generation of silicon photonics. Nat. Commun. 15, 751 (2024).
[2] Lischke, S. et al. Ultra-fast germanium photodiode with 3-dB bandwidth of 265 GHz. Nat. Photonics 15, 925-931 (2021).
[3] Assefa, S., Xia, F. & Vlasov, Y. A. Reinventing germanium avalanche photodetector for nanophotonic on-chip optical interconnects. Nature 464, 80-84 (2010).
[4] Shaikh, S. M. et al. A high-performance all-silicon photodetector enabling telecom-wavelength detection at room temperature. arXiv:2412.05872 (2025).