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Two-dimensional (2D) niobium silicon telluride (Nb2SiTe4) with good stability, a narrow band gap of 0.39 eV, high carrier mobility and superior photoresponsivity, is highly desired for applications in mid-infrared (MIR) detections, ambipolar transistors. Intensive investigations on its ferroelasticity, anisotropic carrier transport, anisotropic thermoelectric property, etc., have been reported recently. Motivated by the above prominent properties and promising applications, we systematically study the electronic properties of single-layer (SL) A2BX4 analogues (A = V, Nb, Ta; B = Si, Ge, Sn; X = S, Se, Te) and find a band-gap anomaly with respect to anion change, which differs from conventional 2D metal chalcogenide. In conventional binary chalcogenide, when cations are kept fixed, the bandgap tends to decrease as the atomic number of anions in the same group increases. However, in SL A2BX4, as atomic number of anions increases, its bandgaps tend to increase, with cations kept fixed. In order to find the underlying mechanism of such an abnormal bandgap, using first-principles calculations, we thoroughly investigate the electronic structures of Nb2SiX4 (X = S, Se, Te) surving as an example. It is found that the valance band maximum (VBM) and conduction band minimum (CBM) are mainly derived from the bonding and antibonding coupling between Nb 4d states. The bandwidth of Nb 4d states determines the relative value of the band gap in Nb2SiX4. We demonstrate that the band gap is largely influenced by the competition effect between Nb—Nb and Nb—X interactions in Nb2SiX4. As the anion atomic number increases, the Nb—Nb bond length increases, yielding an increased bandwidth of Nb 4d state and a smaller bandgap of Nb2SiX4. Meanwhile, as Nb—X bond length increases, the bandwidth of Nb 4d however decreases, yielding a larger bandgap. The interaction between Nb and X should be dominant and responsible for the overall bandgap increase of Nb2SiX4 compared with the Nb—Nb interaction.
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Keywords:
- Nb2SiTe4 /
- band-gap anomaly /
- electronic structures /
- first-principles calculations
[1] Guo Q, Pospischil A, Bhuiyan M, Jiang H, Tian H, Farmer D, Deng B, Li C, Han S J, Wang H, Xia Q, Ma T P, Mueller T, Xia F 2016 Nano. Lett. 16 4648Google Scholar
[2] Youngblood N, Chen C, Koester S J, Li M 2015 Nat. Photonics 9 247Google Scholar
[3] Yuan H, Liu X, Afshinmanesh F, Li W, Xu G, Sun J, Lian B, Curto A G, Ye G, Hikita Y, Shen Z, Zhang S, Chen X, Brongersma M, Hwang H Y, Cui Y 2015 Nat. Nanotechnol. 10 707Google Scholar
[4] Li L, Yu Y, Ye G J, Ge Q, Ou X, Wu H, Feng D, Chen X H, Zhang Y 2014 Nat. Nanotechnol. 9 372Google Scholar
[5] Han C, Hu Z, Gomes L C, Bao Y, Carvalho A, Tan S J R, Lei B, Xiang D, Wu J, Qi D, Wang L, Huo F, Huang W, Loh K P, Chen W 2017 Nano. Lett. 17 4122Google Scholar
[6] Tian H, Deng B, Chin M L, Yan X, Jiang H, Han S J, Sun V, Xia Q, Dubey M, Xia F, Wang H 2016 ACS Nano 10 10428Google Scholar
[7] Castellanos-Gomez A, Vicarelli L, Prada E, Island J O, Narasimha-Acharya K L, Blanter S I, Groenendijk D J, Buscema M, Steele G A, Alvarez J V, Zandbergen H W, Palacios J J, vander Zant H S J 2014 2D Mater. 1 025001Google Scholar
[8] Long M, Gao A, Wang P, Xia H, Ott C, Pan C, Fu Y, Liu E, Chen X, Lu W, Nilges T, Xu J, Wang X, Hu W, Miao F 2017 Sci. Adv. 3 e1700589Google Scholar
[9] Wood J D, Wells S A, Jariwala D, Chen K S, Cho E, Sangwan V K, Liu X, Lauhon L J, Marks T J, Hersam M C 2014 Nano. Lett. 14 6964Google Scholar
[10] Zhang T, Ma Y, Xu X, Lei C, Huang B, Dai Y 2020 J. Phys. Chem. Lett. 11 497Google Scholar
[11] Wang W, Dai S, Li X, Yang J, Srolovitz D J, Zheng Q 2015 Nat. Commun. 6 7853Google Scholar
[12] Zhao M, Xia W, Wang Y, Luo M, Tian Z, Guo Y, Hu W, Xue J 2019 ACS Nano 13 10705Google Scholar
[13] Fang W Y, Li P A, Yuan J H, Xue K H, Wang J F 2020 J. Electron. Mater. 49 959Google Scholar
[14] Ponce’S, Margine E R, Giustino F 2018 Phys. Rev. B 97 121201Google Scholar
[15] Xu B, Xiang H, Yin J, Xia Y, Liu Z 2018 Nanoscale 10 215Google Scholar
[16] Wu M, Zeng X 2016 Nano. Lett. 16 3236Google Scholar
[17] Wang H, Li X, Sun J, Liu Z, Yang J 2017 2D Mater. 4 045020Google Scholar
[18] 罗雄, 孟威威, 陈国旭佳, 管晓溪, 贾双凤, 郑赫, 王建波 2020 69 197102Google Scholar
Luo X, Meng W W, Chen G X J, Guan X X, Jia S F, Zheng H, Wang J B 2020 Acta Phys. Sin. 69 197102Google Scholar
[19] Carrier P, Wei S H 2005 J. Appl. Phys. 97 033707Google Scholar
[20] Wei S H, Zunger A 1997 Phys. Rev. B 55 13605Google Scholar
[21] Ye Z Y, Deng H X, Wu H Z, Li S S, Wei S H, Luo J W 2015 Npj Comput. Mater. 1 15001Google Scholar
[22] Perdew J P, Burke K, Ernzerhof M 1996 Phys. Rev. Lett. 77 3865Google Scholar
[23] Kresse G, Joubert D 1999 Phys. Rev. B 59 1758Google Scholar
[24] Monkhorst H J, Pack J D 1976 Phys. Rev. B 13 5188Google Scholar
[25] Heyd J, Scuseria G E, Ernzerhof M 2003 J. Chem. Phys. 118 8207Google Scholar
[26] Deringer V L, Tchougréeff A L, Dronskowski R 2011 J. Phys. Chem. A 115 5461Google Scholar
[27] Maintz S, Deringer V L, Tchougréeff A L, Dronskowski R 2016 J. Comput. Chem. 37 1030Google Scholar
[28] Wang V, Xu N, Liu J C, Tang G, Geng W T 2021 Comput. Phys. Commun. 267 108033Google Scholar
[29] Wang F, Xu Y, Mu L, Zhang J, Xia W, Xue J, Guo Y, Yang J, Yan H 2022 ACS Nano 16 8107Google Scholar
[30] Boucher F, Zhukov V, Evain M 1996 Inorg. Chem. 35 7649Google Scholar
[31] Hu J, Liu X, Yue C L, Liu J Y, Zhu H W, He J B, Wei J, Mao Z Q, Antipina L Y, Popov Z I, Sorokin P B, Liu T J, Adams P W, Radmanesh S M A, Spinu L, Ji H, Natelson D 2015 Nat. Phys. 11 471Google Scholar
[32] An L, Zhang H, Hu J, Zhu X, Gao W, Zhang J, Xi C, Ning W, Mao Z, Tian M 2018 Phys. Rev. B 97 235133Google Scholar
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图 4 Nb2SiTe4中不同原子间哈密顿轨道布局 (a) Nb-Nb; (b) Nb-Si; (c) Nb-Te; (d) Si-Te; (e)图(b)中红色圆圈的放大部分(横坐标的正(负)表示原子轨道间为成(反)键态, 用图中红(绿)色区域表示)
Figure 4. Crystal orbital Hamilton populations for different interatomic in Nb2SiTe4: (a) Nb-Nb; (b) Nb-Si; (c) Nb-Te; (d) Si-Te; (e) enlarged portion of the red circle in Fig. (b) (The positive (negative) of COHP represents bonding (antibonding) interaction between ions, as colored in red (green)).
表 1 系列Nb2SiTe4构型的参数对比
Table 1. Comparisons of representative Nb2SiTe4-based compounds.
Nb—Nb键长/Å Nb—Te键长/Å Nb 4d带宽/Å 带隙Eg /eV Nb2SiTe4-1 2.91 2.72 1.23 –0.01 Nb2SiTe4-2 2.91 2.76 1.14 0.21 Nb2SiTe4 2.91 2.88 0.69 0.52 Nb2SiTe4-3 2.81 2.71 1.03 0.53 Nb2SiTe4-4 2.75 2.59 1.23 0.25 -
[1] Guo Q, Pospischil A, Bhuiyan M, Jiang H, Tian H, Farmer D, Deng B, Li C, Han S J, Wang H, Xia Q, Ma T P, Mueller T, Xia F 2016 Nano. Lett. 16 4648Google Scholar
[2] Youngblood N, Chen C, Koester S J, Li M 2015 Nat. Photonics 9 247Google Scholar
[3] Yuan H, Liu X, Afshinmanesh F, Li W, Xu G, Sun J, Lian B, Curto A G, Ye G, Hikita Y, Shen Z, Zhang S, Chen X, Brongersma M, Hwang H Y, Cui Y 2015 Nat. Nanotechnol. 10 707Google Scholar
[4] Li L, Yu Y, Ye G J, Ge Q, Ou X, Wu H, Feng D, Chen X H, Zhang Y 2014 Nat. Nanotechnol. 9 372Google Scholar
[5] Han C, Hu Z, Gomes L C, Bao Y, Carvalho A, Tan S J R, Lei B, Xiang D, Wu J, Qi D, Wang L, Huo F, Huang W, Loh K P, Chen W 2017 Nano. Lett. 17 4122Google Scholar
[6] Tian H, Deng B, Chin M L, Yan X, Jiang H, Han S J, Sun V, Xia Q, Dubey M, Xia F, Wang H 2016 ACS Nano 10 10428Google Scholar
[7] Castellanos-Gomez A, Vicarelli L, Prada E, Island J O, Narasimha-Acharya K L, Blanter S I, Groenendijk D J, Buscema M, Steele G A, Alvarez J V, Zandbergen H W, Palacios J J, vander Zant H S J 2014 2D Mater. 1 025001Google Scholar
[8] Long M, Gao A, Wang P, Xia H, Ott C, Pan C, Fu Y, Liu E, Chen X, Lu W, Nilges T, Xu J, Wang X, Hu W, Miao F 2017 Sci. Adv. 3 e1700589Google Scholar
[9] Wood J D, Wells S A, Jariwala D, Chen K S, Cho E, Sangwan V K, Liu X, Lauhon L J, Marks T J, Hersam M C 2014 Nano. Lett. 14 6964Google Scholar
[10] Zhang T, Ma Y, Xu X, Lei C, Huang B, Dai Y 2020 J. Phys. Chem. Lett. 11 497Google Scholar
[11] Wang W, Dai S, Li X, Yang J, Srolovitz D J, Zheng Q 2015 Nat. Commun. 6 7853Google Scholar
[12] Zhao M, Xia W, Wang Y, Luo M, Tian Z, Guo Y, Hu W, Xue J 2019 ACS Nano 13 10705Google Scholar
[13] Fang W Y, Li P A, Yuan J H, Xue K H, Wang J F 2020 J. Electron. Mater. 49 959Google Scholar
[14] Ponce’S, Margine E R, Giustino F 2018 Phys. Rev. B 97 121201Google Scholar
[15] Xu B, Xiang H, Yin J, Xia Y, Liu Z 2018 Nanoscale 10 215Google Scholar
[16] Wu M, Zeng X 2016 Nano. Lett. 16 3236Google Scholar
[17] Wang H, Li X, Sun J, Liu Z, Yang J 2017 2D Mater. 4 045020Google Scholar
[18] 罗雄, 孟威威, 陈国旭佳, 管晓溪, 贾双凤, 郑赫, 王建波 2020 69 197102Google Scholar
Luo X, Meng W W, Chen G X J, Guan X X, Jia S F, Zheng H, Wang J B 2020 Acta Phys. Sin. 69 197102Google Scholar
[19] Carrier P, Wei S H 2005 J. Appl. Phys. 97 033707Google Scholar
[20] Wei S H, Zunger A 1997 Phys. Rev. B 55 13605Google Scholar
[21] Ye Z Y, Deng H X, Wu H Z, Li S S, Wei S H, Luo J W 2015 Npj Comput. Mater. 1 15001Google Scholar
[22] Perdew J P, Burke K, Ernzerhof M 1996 Phys. Rev. Lett. 77 3865Google Scholar
[23] Kresse G, Joubert D 1999 Phys. Rev. B 59 1758Google Scholar
[24] Monkhorst H J, Pack J D 1976 Phys. Rev. B 13 5188Google Scholar
[25] Heyd J, Scuseria G E, Ernzerhof M 2003 J. Chem. Phys. 118 8207Google Scholar
[26] Deringer V L, Tchougréeff A L, Dronskowski R 2011 J. Phys. Chem. A 115 5461Google Scholar
[27] Maintz S, Deringer V L, Tchougréeff A L, Dronskowski R 2016 J. Comput. Chem. 37 1030Google Scholar
[28] Wang V, Xu N, Liu J C, Tang G, Geng W T 2021 Comput. Phys. Commun. 267 108033Google Scholar
[29] Wang F, Xu Y, Mu L, Zhang J, Xia W, Xue J, Guo Y, Yang J, Yan H 2022 ACS Nano 16 8107Google Scholar
[30] Boucher F, Zhukov V, Evain M 1996 Inorg. Chem. 35 7649Google Scholar
[31] Hu J, Liu X, Yue C L, Liu J Y, Zhu H W, He J B, Wei J, Mao Z Q, Antipina L Y, Popov Z I, Sorokin P B, Liu T J, Adams P W, Radmanesh S M A, Spinu L, Ji H, Natelson D 2015 Nat. Phys. 11 471Google Scholar
[32] An L, Zhang H, Hu J, Zhu X, Gao W, Zhang J, Xi C, Ning W, Mao Z, Tian M 2018 Phys. Rev. B 97 235133Google Scholar
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