Tsai Cheng-Hsun, Huang Bo-Jun, Soref Richard A, Sun Greg, Cheng H H, Chang Guo-En
Opt Lett. 2020 Mar 15;45(6):1463-1466. doi: 10.1364/OL.381960.
The 2 µm wavelength band has recently gained increased attention for potential applications in next-generation optical communication. However, it is still challenging to achieve effective photodetection in the 2 µm wavelength band using group-IV-based semiconductors. Here we present an investigation of GeSn resonant-cavity-enhanced photodetectors (RCEPDs) on silicon-on-insulator substrates for efficient photodetection in the 2 µm wavelength band. Narrow-bandgap GeSn alloys are used as the active layer to extend the photodetection range to cover the 2 µm wavelength band, and the optical responsivity is significantly enhanced by the resonant cavity effect as compared to a reference GeSn photodetector. Temperature-dependent experiments demonstrate that the GeSn RCEPDs can have a wider photodetection range and higher responsivity in the 2 µm wavelength band at higher temperatures because of the bandgap shrinkage. These results suggest that our GeSn RCEPDs are promising for complementary metal-oxide-semiconductor-compatible, efficient, uncooled optical receivers in the 2 µm wavelength band for a wide range of applications.
2微米波长波段最近在下一代光通信的潜在应用中受到了越来越多的关注。然而，使用基于IV族的半导体在2微米波长波段实现有效的光电探测仍然具有挑战性。在此，我们展示了对绝缘体上硅衬底上的锗锡共振腔增强型光电探测器（RCEPD）的研究，以在2微米波长波段进行高效光电探测。窄带隙锗锡合金用作有源层，将光电探测范围扩展至覆盖2微米波长波段，并且与参考锗锡光电探测器相比，共振腔效应显著提高了光响应度。温度相关实验表明，由于带隙收缩，锗锡RCEPD在较高温度下在2微米波长波段可具有更宽的光电探测范围和更高的响应度。这些结果表明，我们的锗锡RCEPD有望用于2微米波长波段的互补金属氧化物半导体兼容、高效、非制冷光接收器，以实现广泛应用。
