Novel Nano material Research group

Publication

Journals

  • Single-crystal growth
  • Wafer-scale single-crystal hexagonal boron nitride film via self-collimated grain formation
  • Joo Song Lee, Soo Ho Choi, Seok Joon Yun, Yong In Kim, Stephen Boandoh, Ji-Hoon Park, Bong Gyu Shin, Hayoung Ko, Seung Hee Lee, Young-Min Kim, Young Hee Lee, Ki Kang Kim, and Soo Min Kim. Science 362, 817-821 2018
  • We discover a method of synthesizing wafer-scale single-crystal (SC) hexagonal boron nitride (hBN) monolayer film. In contrary to traditional epitaxial growth, liquid gold substrate allows the self-collimation of circular hBN grains, eventually forming an SC hBN film on a wafer scale. SC hBN serves the growth template for SC-Graphene/hBN heterostructure and SC tungsten disulfide. This is the first…
  • 2D alloy
  • Tailoring Domain Morphology in Monolayer NbSe2 and WxNb1-xSe2 Heterostructure
  • ACS Nano 14, 8784-8792 2020
  • 2D material properties, including electronic and optical properties, can be adjusted through alloying. In this work, we dope NbSe2 with W to make a lateral heterostructure with semiconducting WSe2 on the inside and metallic NbSe2 on the outside. The each point of doping level is characterized by STEM (Scanning Transmission Electron Microscopy) and well correlated with optical (Raman, Photoluminesc…
  • Catalyst
  • Substitutional VSn Nanodispersed in MoS2 Film for Pt-scalable Catalyst
  • Frederick Osei-Tutu Agyapong-Fordjour, Seok Joon Yun, Hyung-Jin Kim, Wooseon Choi, Soo Ho Choi, Laud Anim Adofo, Stephen Boandoh, Yong In Kim, Soo Min Kim, Young-Min Kim, Young Hee Lee, Young-Kyu Han, and Ki Kang Kim. arXiv:2010.10908 2020
  • This work demonstrate the basal plane activation of 2D MoS2 via substituted V atoms as VSn unit in 2H-MoS2 lattice. The VSn units acts as acive sites and also charge transfer pathways for efficient hydrogen evolution.
  • Device application
  • Synthesis of hexagonal boron nitride heterostructures for 2D van der Waals electronics
  • Ki Kang Kim, Hyun Seok Lee, and Young Hee Lee. Chem. Soc. Rev. 47, 6342-6369 2018
  • This work reviews the recent progress of the large-area synthesis of hBN and other related vdW heterostructures via CVD, and artificial construction of vdW heterostructures and 2D vdW electronics based on hBN, in terms of charge fluctuations, passivation, gate dielectrics, tunneling, Coulombic interactions, and contact resistantces. The challenges and future perspectives for practical applications…
149. Harnessing Persistent Photocurrent in a 2D Semiconductor-Polymer Hybrid Structure: Electron Trapping and Fermi Level Modulation for Optoelectronic Memory
Author
Seungho Bang, Wooyoung Kang, Dohyeong Kim, Hyeong Chan Suh, Dong Hyeon Kim, Chan Kwon, Jieun Jo, Ji-Hong Kim, Hayoung Ko, Ki Kang Kim, Jinho Ahn, Mun Seok Jeong*
Journal
Nano Letters
Volume(Issue)
24(32)
Page
9889-9897
Publication Date
2024.08.14
Project Number
2022R1A2C2091475
Recently, 2D semiconductor-based optoelectronic memory has been explored to overcome the limitations of conventional von Neumann architectures by integrating optical sensing and data storage into one device. Persistent photocurrent (PPC), essential for optoelectronic memory, originates from charge carrier trapping according to the Shockley–Read–Hall (SRH) model in 2D semiconductors. The quasi-Fermi level position influences the activation of charge-trapping sites. However, the correlation between quasi-Fermi level modulations and PPC in 2D semiconductors has not been extensively studied. In this study, we demonstrate optoelectronic memory based on a 2D semiconductor–polymer hybrid structure and confirm that the underlying mechanism is charge trapping, as the SRH model explains. Under light illumination, electrons transfer from polyvinylpyrrolidone to p-type tungsten diselenide, resulting in high-level injection and majority carrier-type transitions. The quasi-Fermi level shifts upward with increasing temperature, improving PPC and enabling optoelectronic memory at 433 K. Our findings offer valuable insights into optimizing 2D semiconductor-based optoelectronic memory.