Mg2Si

材质：硅化镁 (Mg 2 Si)

基本信息

硅化镁是一种深蓝色或微紫色的化合物。结晶时，Mg2Si 显示面心立方晶格排列。这种排列具有反萤石结构。  Mg2Si 由于其半导体特性而被用作铝合金的添加剂、锂离子电池的负极材料以及光伏应用。

 

光伏应用

由于晶体生长困难，硅化镁主要仅用于薄膜应用。镁的低凝聚系数和Mg2Si的势垒行为使得难以生长足够厚度的Mg2Si。用于生产硅化镁薄膜的成功方法包括：分子束外延、固相生长和离子束合成。

 

300 K 时的基本参数

Crystal structure: Antifluorite [1]              

Debye temperature: 417 K T = 300 K [1]                         

Density: 1.88 g cm -3                                           [1]         

Dielectric constants: ɛ(0) 20 [1]

                                                                               ɛ(∞) 13.3

Effective masses: m n           0.46 m 0                                                [1]

                                                                               m p           0.87 m 0                                               [1]

Electron affinity: 3.59 eV [5]

Lattice constant: a = 6.338 Å [1]                                                    

能带结构和载流子浓度

        能带结构和载流子浓度

 

有关能带结构的信息可以在 Madelung, O. (2004) 中找到。半导体：数据手册。 （第三版，第 1595-1605 页）. Springer. [1]

 

       

 

温度依赖性

 

三种 n 型样品在混合传导范围内的电导率与温度的关系图可以在 Madelung, O. (2004) 中找到。半导体：数据手册。 （第三版，第 1595-1605 页）. Springer. [1].

Mg2Si、Mg2Ge 和 Mg2Sn 的热导率与温度的关系图可在 Madelung, O. (2004) 中找到。半导体：数据手册。 （第三版，第 1595-1605 页）. Springer.b [1].

 

 

        高掺杂水平下能隙缩小

        有效质量和态密度

        施主和受主

                        施主:                Bi                                            [3]

杂质形成能数据可在 Zwolenski, P.、Tobola, J.、Kaprzyk, S., A Theory sarch for effective dopants in Mg2X (X = Si, Ge, Sn) Thermoelectrical Materials 中找到。 Springer Boston，第 40 卷，第 5 期，2011 年 5 月 1 日，第 889-897 页，ISSN 0361-5235，10.1007/s11664-011-1624-y。 [4]

电气特性

        电性能基本参数

                Energy gap:                                                                        0.77 eV                Indirect                                [7]         

                Conduction type:                                                                n-type                                                                [3]

Energy spin-orbital splitting:                                            0.03 eV                                                              [6]

Intrinsic carrier concentration:                                 ni = 1*1014 cm-3        T= 300 K                             [1]         

Electron Carrier mobility:                                                  370 cm2/V s                                                      [7]

Hole mobility                                                                       70 cm2/V s                                                         [7]

 

 

 

  流动性和霍尔效应

               

Mg2Si 霍尔迁移率与温度的关系图可以在 Madelung, O. (2004) 中找到。半导体：数据手册。 （第三版，第 1595-1605 页）. Springer [1].                                                                                                                                                         

光学特性

折射率                                        3.591                                                                                     [2]

热性能

晶格热容:                        Cv = 67.87 J mol-1 K-1            T= 300 K                                     [1]

机械性能、弹性常数、晶格振动

        基本参数                                                                                               

密度:                                        1.88 g cm-3                                                                      [1]

    弹性常数

                弹性常数：

                c11                                12.1(2)*1011 dyn cm-2     T=300 K                                [1]         

                c12                                2.2(2)*1011 dyn cm-2      

                c44                                4.64(5)*1011 dyn cm-2    

 

根据声速数据计算出的 Mg2Si 弹性模量与温度的关系图可以在 Madelung, O. (2004) 中找到。半导体：数据手册。 （第三版，第 1595-1605 页）. Springer. [1]

 

                                                                                                                                                                               

    

   声波速度

                声速:

                νLA                          7.68*105 cm s-1                  T= 300 K               [110] -direction                                 [1]         

                νTA,I                        4.83*105 cm s-1                                                  [110] -direction, lower branch

                νTA,II                       4.97*105 cm s-1                                                   [110] -direction, upper branch

                νLA                          7.65*105 cm s-1                                                   [111] –direction

                νTA                          4.95*105 cm s-1                                                   [111] -direction

        声子频率

 

                νTO(Г15)                 8.0*1012s-1           T=300 K                                                [1]

                νLO(Г15)                 9.8*1012s-1

                                                10.56*1012s-1      T= 77 K

                ν(Г25’)                    7.75*1012s-1        T=300 K               

                                                7.86*1012s-1        T=77 K  

 

 

 

 

参考

 

[1] Madelung, O. (2004). Semiconductors: Data handbook. (3rd ed., pp. 1595-1605). Springer.

[2] Benhelal, O., Chahed, A., Laksari, S., Abbar, B., Bouhafs, B. and Aourag, H. (2005), First-principles calculations of the structural, electronic and optical properties of IIA–IV antifluorite compounds. Phys. Status Solidi B, 242: 2022–2032. doi: 10.1002/pssb.200540063

(http://onlinelibrary.wiley.com/doi/10.1002/pssb.200540063/abstract)

 

[3] Jun-ichi Tani, Hiroyasu Kido, Thermoelectric properties of Bi-doped Mg2Si semiconductors, Physica B: Condensed Matter, Volume 364, Issues 1–4, 15 July 2005, Pages 218-224, ISSN 0921-4526, 10.1016/j.physb.2005.04.017.

(http://www.sciencedirect.com/science/article/pii/S092145260500709X)

 

[4] Zwolenski, P., Tobola, J., Kaprzyk, S., A theoretical search for efficient dopants in Mg2X ( X = Si, Ge, Sn) Thermoelectrical materials. Springer Boston, Volume 40, Issue 5, 1 May 2011, Pages 889-897, ISSN 0361-5235, 10.1007/s11664-011-1624-y.

(http://dx.doi.org/10.1007/s11664-011-1624-y)

 

[5] A. Atanassov, M. Baleva, On the band diagram of Mg2Si/Si heterojunction as deduced from optical constants dispersions, Thin Solid Films, Volume 515, Issue 5, 22 January 2007, Pages 3046-3051, ISSN 0040-6090, 10.1016/j.tsf.2006.08.015.

(http://www.sciencedirect.com/science/article/pii/S0040609006010054)

 

[6] F. Vazquez*, Richard A. Forman, and Manuel Cardona. Electroreflectance Measurements on Mg2Si, Mg2Ge, and Mg2Sn. Department of Physics, Brown University, Providence, Rhode Island 02912. 10.1103/PhysRev.176.905

(http://prola.aps.org/abstract/PR/v176/i3/p905_1)

 

 
 
 
[7] Yoji Imai, Akio Watanabe, Masakazu Mukaida, Electronic structures of semiconducting alkaline-earth metal silicides, Journal of Alloys and Compounds, Volume 358, Issues 1–2, 25 August 2003, Pages 257-263, ISSN 0925-8388, 10.1016/S0925-8388(03)00037-9.

(http://www.sciencedirect.com/science/article/pii/S0925838803000379)

 

主要由犹他大学本科生 Jeff Provost 和 Carina Hahn 与 Mike Scarpulla 教授合作开发。 Caitlin Arndt、Christian Robert、Katie Furse、Jash Sayani 和 Liz Lund 也做出了贡献。这项工作得到了美国国家科学基金会材料世界网络计划奖 1008302 的全力支持。这些页面是一项正在进行的工作，我们征求世界各地知识渊博的各方的意见，以获取更准确或更多的信息。请联系 [email protected] 提出此类建议。