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Van der Waals Epitaxial Growth of Atomic Layered HfS 2 Crystals for Ultrasensitive Near‐Infrared Phototransistors
Author(s) -
Fu Lei,
Wang Feng,
Wu Bin,
Wu Nian,
Huang Wei,
Wang Hanlin,
Jin Chuanhong,
Zhuang Lin,
He Jun,
Fu Lei,
Liu Yunqi
Publication year - 2017
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.201700439
Subject(s) - responsivity , materials science , van der waals force , density functional theory , electron mobility , band gap , photodetection , infrared , epitaxy , optoelectronics , graphene , condensed matter physics , nanotechnology , photodetector , computational chemistry , optics , chemistry , layer (electronics) , physics , organic chemistry , molecule
As a member of the group IVB transition metal dichalcogenides (TMDs) family, hafnium disulfide (HfS 2 ) is recently predicted to exhibit higher carrier mobility and higher tunneling current density than group VIB (Mo and W) TMDs. However, the synthesis of high‐quality HfS 2 crystals, sparsely reported, has greatly hindered the development of this new field. Here, a facile strategy for controlled synthesis of high‐quality atomic layered HfS 2 crystals by van der Waals epitaxy is reported. Density functional theory calculations are applied to elucidate the systematic epitaxial growth process of the S‐edge and Hf‐edge. Impressively, the HfS 2 back‐gate field‐effect transistors display a competitive mobility of 7.6 cm 2 V −1 s −1 and an ultrahigh on/off ratio exceeding 10 8 . Meanwhile, ultrasensitive near‐infrared phototransistors based on the HfS 2 crystals (indirect bandgap ≈1.45 eV) exhibit an ultrahigh responsivity exceeding 3.08 × 10 5 A W −1 , which is 10 9 ‐fold higher than 9 × 10 −5 A W −1 obtained from the multilayer MoS 2 in near‐infrared photodetection. Moreover, an ultrahigh photogain exceeding 4.72 × 10 5 and an ultrahigh detectivity exceeding 4.01 × 10 12 Jones, superior to the vast majority of the reported 2D‐materials‐based phototransistors, imply a great promise in TMD‐based 2D electronic and optoelectronic applications.