Ultrahigh Responsivity Photodetectors of Two-dimensional Covalent Organic Frameworks Integrated on Graphene
22 Oct 2019
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Xiong Yi-feng
•
Liao Qiao-bo
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Huang Zheng-ping
•
Huang Xin
•
Ke Can
•
Zhu Heng-tian
•
Dong Chen-yu
•
Wang Hao-shang
•
Xi Kai
•
Zhan Peng
•
Xu Fei
•
Lu Yan-qing
Two dimensional (2D) materials exhibit superior properties in electronic and
optoelectronic fields. The wide demand for high performance optoelectronic
devices promotes the exploration of diversified 2D materials...Recently, 2D
covalent organic frameworks (COFs) have emerged as next-generation layered
materials with predesigned pi electronic skeletons and highly ordered
topological structures, which are promising for tailoring their optoelectronic
properties. However, COFs are usually produced as solid powders due to
anisotropic growth, making them unreliable to integrate into devices. Here, by
selecting tetraphenylethylene (TPE) monomers with photoelectric activity, we
designed and synthesized photosensitive 2D COFs with highly ordered topologies
and grew 2D COFs in situ on graphene to form well ordered COF graphene
heterostructures. Ultrasensitive photodetectors were successfully fabricated
with the COFETBC TAPT graphene heterostructure and exhibited an excellent
overall performance. Moreover, due to the high surface area and the polarity
selectivity of COFs, the photosensing properties of the photodetectors can be
reversibly regulated by specific target molecules. Our research provides new
strategies for building advanced functional devices with programmable material
structures and diversified regulation methods, paving the way for a generation
of high performance applications in optoelectronics and many other fields.(read more)