Send to

Choose Destination
ACS Nano. 2019 Jan 22;13(1):913-921. doi: 10.1021/acsnano.8b08758. Epub 2019 Jan 2.

Waveguide-Integrated Black Phosphorus Photodetector for Mid-Infrared Applications.

Huang L1,2, Dong B1,3, Guo X4, Chang Y1, Chen N1, Huang X1,2, Liao W1,2, Zhu C1,2, Wang H4, Lee C1,3, Ang KW1,2.

Author information

Department of Electrical and Computer Engineering , National University of Singapore , 4 Engineering Drive 3 , Singapore 117583.
Centre for Advanced 2D Materials , National University of Singapore , 6 Science Drive 2 , Singapore 117546.
NUS Graduate School for Integrative Sciences & Engineering , National University of Singapore , 28 Medical Drive , Singapore 117456.
School of Electrical and Electronic Engineering , Nanyang Technological University , 50 Nanyang Avenue , Singapore 639798.


Midinfrared (MIR), which covers numerous molecular vibrational fingerprints, has attracted enormous research interest due to its promising potential for label-free and damage-free sensing. Despite intense development efforts, the realization of waveguide-integrated on-chip sensing system has seen very limited success to date. The huge lattice mismatch between silicon and the commonly used detection materials such as HgCdTe, III-V, or II-VI compounds has been the key bottleneck that hinders their integration. Here, we realize an integration of silicon-on-insulator (SOI) waveguides with black phosphorus (BP) photodetectors. When operating near BP's cutoff wavelength where absorption is weak, the light-BP interaction is enhanced by exploiting the optical confinement in the Si waveguide and grating structure to overcome the limitation of absorption length constrained by the BP thickness. Devices with different BP crystal orientation and thickness are compared in terms of their responsivity and noise equivalent power (NEP). Spectral photoresponse from 3.68 to 4.03 μm was investigated. Additionally, power-dependent responsivity and gate-tunable photocurrent were also studied. At a bias of 1 V, the BP photodetector achieved a responsivity of 23 A/W at 3.68 μm and 2 A/W at 4 μm and a NEP less than 1 nW/Hz1/2 at room temperature. The integration of passive Si photonics and active BP photodetector is envisaged to offer a potential pathway toward the realization of integrated on-chip systems for MIR sensing applications.


black phosphorus; integration; mid-infrared; photodetector; silicon photonics


Supplemental Content

Full text links

Icon for American Chemical Society
Loading ...
Support Center