Low-dimensional Main Group Element Semiconductors of the SnIP-type

该项目将涉及低维SnIP型无机双螺旋化合物的合成、表征和应用。SnIP是由一个外[SnI]螺旋和一个内[P]螺旋组成的双螺旋的六边形棒状排列。从微晶SnIP开始，我们打算通过化学和机械剥离来制造直径小于1nm的双螺旋单链纳米纤维（宽高比大）。在成功制备这种纳米纤维的情况下，我们期望其具有非凡的机械、光学和电子性能。在适当的溶剂中悬浮SnIP后，我们打算在各种衬底上制造和表征薄层器件。这种器件的可能应用是太阳能电池、传感器和场效应晶体管。为了评价SnIP的相形成和生长，计划进行原位中子衍射实验。我们期望从格勒诺布尔的一组D20测量中得出增长速度和机制。所获得的知识可以转移到优化合成条件，直接在衬底上制备SnIP薄膜。与SnIP类似，我们打算用通式MXPn （M = Ge, Sn, Pb; X = Cl, Br， I和Pn = P, As, Sb）制备更多的双螺旋化合物。选定的代表将用于制造设备，如在SnIP的情况下。对于所有MXPn相，从SnIP开始，我们将尝试用合适的元素掺杂它们来诱导或增加n型和p型电导率。为了改善剥离倾向和检验无机双螺旋化合物的化学性质，我们将MXPn与路易斯碱反应，得到酸碱加合物。首先，实验表明功能化硼酸盐能显著改善悬浮倾向。在此基础上，我们打算评价与路易斯碱的MXPn化合物的反应性。在该项目成功实现的情况下，MXPn化合物将定义一类新的柔性、机械坚固、低维半导体，具有半导体应用的前景。

The proposed project will deal with the synthesis, characterization and usage of low-dimensional, inorganic double helix compounds of the SnIP type. SnIP consists of a hexagonal rod-packed arrangement of double helices, composed by an outer [SnI] and an inner [P] helix.Starting with microcrystalline SnIP we intend to fabricate double helical, single-chain nano fibers down to 1 nm in diameter (an large aspect ratios) by chemical and mechanical exfoliation. In the case of a successful preparation of such nano fibers, we expect extraordinary mechanical, optical and electronic properties. After suspending SnIP in suitable solvents we intend to fabricate and characterize thin-layer devices on various substrates. Possible applications for such devices are solar cells, sensors and field effect transistors.To evaluate the phase formation and growth of SnIP, an in situ neutron diffraction experiment is planned. We expect to derive the growth speed and mechanism from a set of D20 measurements at the ILL, Grenoble. The gained knowledge can be transferred to optimize the synthesis conditions to prepare thin-films of SnIP directly on substrates.In Analogy to SnIP we intend to prepare more double helical compounds with the general formula MXPn (with M = Ge, Sn, Pb; X = Cl, Br, I und Pn = P, As, Sb). Selected representatives will be used to fabricate devices like in the case of SnIP.For all MXPn phases, starting with SnIP, we will try to dope them with suitable elements to induce or increase n- and p-type conductivity. To improve the exfoliation tendency and to examine the chemistry of inorganic double helix compounds we will react MXPn with Lewis bases, in order to get acid-base adducts. First experiments show that functionalized borates can improve the suspension tendency drastically. Based on this aspect we intend to evaluate the reactivity of MXPn compounds with Lewis bases.In the case of a successful realization of this project MXPn compounds will define a new class of flexible, mechanically robust, low-dimensional semiconductors with a perspective in semiconductor applications.