TY - JOUR
T1 - Multifunctional Binary Monolayers GexPy
T2 - Tunable Band Gap, Ferromagnetism, and Photocatalyst for Water Splitting
AU - Li, Pengfei
AU - Zhang, Wei
AU - Li, Dongdong
AU - Liang, Changhao
AU - Zeng, Xiao Cheng
PY - 2018/6/13
Y1 - 2018/6/13
N2 - The most stable structures of two-dimensional GexPy and GexAsy monolayers with different stoichiometries (e.g., GeP, GeP2, and GeP3) are explored systematically through the combination of the particle-swarm optimization technique and density functional theory optimization. For GeP3, we show that the newly predicted most stable C2/m structure is 0.16 eV/atom lower in energy than the state-of-the-art P3 m1 structure reported previously (Nano Lett. 2017, 17, 1833). The computed electronic band structures suggest that all the stable and metastable monolayers of GexPy are semiconductors with highly tunable band gaps under the biaxial strain, allowing strain engineering of their band gaps within nearly the whole visible-light range. More interestingly, the hole doping can convert the C2/m GeP3 monolayer from nonmagnetic to ferromagnetic because of its unique valence band structure. For the GeP2 monolayer, the predicted most stable Pmc21 structure is a (quasi) direct-gap semiconductor that possesses a high electron mobility of ∼800 cm2 V-1 s-1 along the ka direction, which is much higher than that of MoS2 (∼200 cm2 V-1 s-1). More importantly, the Pmc21 GeP2 monolayer not only can serve as an n-type channel material in field-effect transistors but also can be an effective catalyst for splitting water.
AB - The most stable structures of two-dimensional GexPy and GexAsy monolayers with different stoichiometries (e.g., GeP, GeP2, and GeP3) are explored systematically through the combination of the particle-swarm optimization technique and density functional theory optimization. For GeP3, we show that the newly predicted most stable C2/m structure is 0.16 eV/atom lower in energy than the state-of-the-art P3 m1 structure reported previously (Nano Lett. 2017, 17, 1833). The computed electronic band structures suggest that all the stable and metastable monolayers of GexPy are semiconductors with highly tunable band gaps under the biaxial strain, allowing strain engineering of their band gaps within nearly the whole visible-light range. More interestingly, the hole doping can convert the C2/m GeP3 monolayer from nonmagnetic to ferromagnetic because of its unique valence band structure. For the GeP2 monolayer, the predicted most stable Pmc21 structure is a (quasi) direct-gap semiconductor that possesses a high electron mobility of ∼800 cm2 V-1 s-1 along the ka direction, which is much higher than that of MoS2 (∼200 cm2 V-1 s-1). More importantly, the Pmc21 GeP2 monolayer not only can serve as an n-type channel material in field-effect transistors but also can be an effective catalyst for splitting water.
KW - band structure
KW - ferromagnetism
KW - semiconductor
KW - two-dimensional
KW - water splitting
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U2 - 10.1021/acsami.8b05655
DO - 10.1021/acsami.8b05655
M3 - Article
C2 - 29792327
AN - SCOPUS:85047600822
VL - 10
SP - 19897
EP - 19905
JO - ACS applied materials & interfaces
JF - ACS applied materials & interfaces
SN - 1944-8244
IS - 23
ER -