Towards the controlled CVD growth of graphitic B-C-N atomic layer films: The key role of B-C delivery molecular precursor
Towards the controlled CVD growth of graphitic B-C-N atomic layer films: The key role of B-C delivery molecular precursor
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石墨 B-C-N 原子层薄膜的受控 CVD 生长：B-C 传递分子前体的关键作用
DOI：
10.1007/s12274-016-1018-9
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发表时间：
2016
期刊：
影响因子：
9.9
通讯作者：
Wang Enge
中科院分区：
文献类型：
--
作者：
Wang Hao;Zhao Chong;Liu Lei;Xu Zhi;Wei Jiake;Wang Wenlong;Bai Xuedong;Wang Enge
类似石墨烯的三元体系B-C-N原子层材料具有高度可调的电子性能和大量的潜在应用。然而，到目前为止，B-C-N原子层的实验合成通常会产生由纯C和BN结构域组成的微观相分离结构。此外，用均匀的原子排列生长真正的三元B-C-N相层被证明是非常具有挑战性的。在设计一种更好地控制化学气相沉积(CVD)生长B-C-N原子层薄膜的过程中，我们选择了三甲基硼烷(TMB)作为分子前体，它是一种具有预先存在的B-C键的气态有机硼化合物，与氨(NH3)气体反应作为硝化剂。使用这种独特的B-C输送前驱体，可以成功地合成高质量和大面积的B-C-N原子层薄膜。此外，TMB/NH3反应物组合可以通过调节两个气态反应物的相对分压来提供高水平的可调性和对B-C-N原子层的整体化学成分的控制。电输运测量表明，在生长的B-C-N原子层中可以打开一个有限的能隙，它的可调性本质上取决于C原子与BN原子的相对组成。在严格控制实验的基础上，我们发现TMB分子前驱体中预先存在的B-C键对有效地减少C和BN相的偏析问题起到了关键作用，从而促进了真正的三元B-C-N相原子层的形成。
Graphene-like, ternary system B–C–N atomic layer materials promise highly tunable electronic properties and a plethora of potential applications. However, thus far, experimental synthesis of the B–C–N atomic layers normally yields a microscopic phase-segregated structure consisting of pure C and BN domains. Further, growing the truly ternary B–C–N phase layers with homogenous atomic arrangements has proven to be very challenging. Here, in designing a bettercontrolled process for the chemical vapor deposition (CVD) growth of B–C–N atomic layer films with the minimized C and BN phase segregation, we selected trimethyl borane (TMB), a gaseous organoboron compound with pre-existing B–C bonds, as the molecular precursor to react with ammonia (NH3) gas that serves as the nitrification agent. The use of this unique B–C delivery precursor allows for the successful synthesis of high-quality and large-area B–C–N atomic layer films. Moreover, the TMB/NH3reactant combination can offer a high level of tunability and control of the overall chemical composition of B–C–N atomic layers by regulating the relative partial pressure of two gaseous reactants. Electrical transport measurements show that a finite energy gap can be opened in the as-grown B–C–N atomic layers and its tunability is essentially dependent on the relative C to BN atomic compositions. On the basis of carefully controlled experiments, we show that the pre-existing B–C bonds in the TMB molecular precursor have played a crucial role in effectively reducing the C and BN phase segregation problem, thereby facilitating the formation of truly ternary B–C–N phase atomic layers.