GeSn Waveguide Photodetectors with Vertical <i>p–i–n</i> Heterostructure for Integrated Photonics in the 2 μm Wavelength Band

The 2 μm wavelength band (1800–2100 nm) emerges as a promising candidate for next‐generation optical communication. As result, silicon photonic platforms acquire great interest since they offer the ultimate minimization of systems applications. However, large bandgap and indirectness structure conventional SiGe alloy prevent their utilization efficient photodetection in band. To overcome this drawback, complementary metal‐oxide semiconductor (CMOS)‐compatible GeSn waveguide photodetectors (WGPDs) with vertical p – i n heterojunction configuration that can operate is demonstrated. proposed photodetector incorporates 5.28% Sn into active layer, which redshifts range to 2090 nm. In addition, longer light–matter interaction length good confinement WGPD enhance responses significantly. achieves responsivity up 0.52 A W −1 detectivity 7.9 × 10 8 cm Hz ½ at room temperature. These results indicate developed WGPDs are candidates integrated photonics