Open AccessSurface plasmon enhanced GeSn photodetectors operating at 2 µm
Author(s) -
Hao Zhou,
Lin Zhang,
Jianhua Tong,
Shaoteng Wu,
Bongkwon Son,
Qimiao Chen,
Dao Hua Zhang,
Chuan Seng Tan
Publication year - 2021
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.420543
Subject(s) - responsivity , photodetector , materials science , optoelectronics , surface plasmon , grating , optics , plasmon , surface plasmon resonance , polarization (electrochemistry) , nanotechnology , physics , nanoparticle , chemistry
Au-hole array and Au-GeSn grating structures were designed and incorporated in GeSn metal-semiconductor-metal (MSM) photodetectors for enhanced photo detection at 2 µm. Both plasmonic structures are beneficial for effective optical confinement near the surface due to surface plasmon resonance (SPR), contributing to an enhanced responsivity. The responsivity enhancement for Au hole-array structure is insensitive to the polarization direction, while the enhancement for Au-GeSn grating structure depends on the polarization direction. The responsivity for GeSn photodetector with Au hole-array structure has ∼50% reinforcement compared with reference photodetector. On the other hand, Au-GeSn grating structure benefits a 3× enhanced responsivity of 0.455 A/W at 1.5V under TM-polarized illumination. The achieved responsivity is among the highest values for GeSn photodetectors operating at 2 µm. The plasmonic GeSn photodetectors in this work offer an alternative solution for high-efficiency photo detection, manifesting their great potentials as candidates for 2 µm optical communication and other emerging applications.