Affiliation:
1. Shanghai University
2. Shanghai Jiao Tong University
Abstract
Lithium niobate (LN) photonics has gained significant interest for
their distinct material properties. However, achieving monolithically
integrated photodetectors on lithium niobate on an insulator (LNOI)
platform for communication wavelengths remains a challenge due to the
large bandgap and extremely low electrical conductivity of LN
material. A two-dimensional (2D) material photodetector is an ideal
solution for LNOI photonics with a strong light–matter interaction and
simple integration technique. In this work, a van der Waals
heterostructure photodiode composed of a p-type black phosphorus layer
and an n-type MoS2 layer is successfully demonstrated for
photodetection at communication wavelengths on a LNOI platform. The
LNOI waveguide-integrated BP-MoS2 photodetector exhibits a
dark current as low as 0.21 nA and an on/off ratio exceeding 200 under
zero voltage bias with an incident power of 13.93 µW. A responsivity
as high as 1.46 A/W is achieved at −1 V bias with a reasonable dark
current around 2.33 µA. With the advantages of high responsivity, low
dark current, and simple fabrication process, it is promising for the
monolithically integrated photodetector application for LNOI photonic
platforms at communication wavelengths.
Funder
National Natural Science Foundation of
China
Shanghai Key Laboratory of Chips and
Systems for Intelligent Connected Vehicle
Shanghai Collaborative Innovation Center
of Intelligent Sensing Chip Technology