Open AccessWeak Interlayer Interaction in 2D Anisotropic GeSe 2
Author(s) -
Yang Yusi,
Wang Xia,
Liu ShunChang,
Li Zongbao,
Sun Zhaoyang,
Hu Chunguang,
Xue DingJiang,
Zhang Gengmin,
Hu JinSong
Publication year - 2019
Publication title -
advanced science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.388
H-Index - 100
ISSN - 2198-3844
DOI - 10.1002/advs.201801810
Subject(s) - materials science , raman spectroscopy , density functional theory , anisotropy , band gap , germanium , brillouin zone , diselenide , condensed matter physics , computational chemistry , optics , selenium , chemistry , optoelectronics , silicon , physics , metallurgy
Germanium diselenide (GeSe 2 ) has recently emerged as a new member of in‐plane anisotropic 2D materials, notable for its wide bandgap of 2.74 eV, excellent air stability, and high performance in polarization‐sensitive photodetection. However, the interlayer interaction in GeSe 2 has never been reported, which usually plays an important role in layer‐number‐dependent physical properties. Here, the interlayer coupling in GeSe 2 is systematically investigated from theory to experiment. Unexpectedly, all of density functional theory (DFT) calculations about layer‐dependent band structures, cleavage energy, binding energy, translation energy, and interlayer differential charge density demonstrate the much weaker interlayer interaction in GeSe 2 when compared with black phosphorus (BP). Furthermore, both thickness‐dependent and temperature‐dependent Raman spectra of GeSe 2 flakes, which exhibit no detectable changes of Raman peaks with the increase in thickness and a small first‐order temperature coefficient of −0.0095 cm −1 K −1 , respectively, experimentally confirm the weakly coupled layers in GeSe 2 . The results establish GeSe 2 as an unusual member of in‐plane anisotropic 2D materials with weak interlayer interaction.