Tummala Pinaka Pani, Martella Christian, Molle Alessandro, Lamperti Alessio
Institute for Microelectronics and Microsystems (CNR-IMM), Unit of Agrate Brianza, via C. Olivetti 2, I-20864 Agrate Brianza, Italy.
Dipartimento di Matematica e Fisica, Università Cattolica del Sacro Cuore, via della Garzetta 48, I-25133 Brescia, Italy.
Nanomaterials (Basel). 2022 Mar 16;12(6):973. doi: 10.3390/nano12060973.
Molybdenum disulfide (MoS) got tremendous attention due to its atomically thin body, rich physics, and high carrier mobility. The controlled synthesis of large area and high crystalline monolayer MoS nanosheets on diverse substrates remains a challenge for potential practical applications. Synthesizing different structured MoS nanosheets with horizontal and vertical orientations with respect to the substrate surface would bring a configurational versatility with benefit for numerous applications, including nanoelectronics, optoelectronics, and energy technologies. Among the proposed methods, ambient pressure chemical vapor deposition (AP-CVD) is a promising way for developing large-scale MoS nanosheets because of its high flexibility and facile approach. Here, we show an effective way for synthesizing large-scale horizontally and vertically aligned MoS on different substrates such as flat SiO/Si, pre-patterned SiO and conductive substrates (TaN) benefit various direct TMDs production. In particular, we show precise control of CVD optimization for yielding high-quality MoS layers by changing growth zone configuration and the process steps. We demonstrated that the influence of configuration variability by local changes of the S to MoO precursor positions in the growth zones inside the CVD reactor is a key factor that results in differently oriented MoS formation. Finally, we show the layer quality and physical properties of as-grown MoS by means of different characterizations: Raman spectroscopy, scanning electron microscopy (SEM), photoluminescence (PL) and X-ray photoelectron spectroscopy (XPS). These experimental findings provide a strong pathway for conformally recasting AP-CVD grown MoS in many different configurations (i.e., substrate variability) or motifs (i.e., vertical or planar alignment) with potential for flexible electronics, optoelectronics, memories to energy storage devices.
二硫化钼（MoS）因其原子级薄的结构、丰富的物理特性和高载流子迁移率而备受关注。在各种衬底上可控合成大面积、高结晶度的单层MoS纳米片对于潜在的实际应用而言仍是一项挑战。合成相对于衬底表面具有水平和垂直取向的不同结构的MoS纳米片将带来构型的多样性，这有利于众多应用，包括纳米电子学、光电子学和能源技术。在已提出的方法中，常压化学气相沉积（AP-CVD）因其高灵活性和简便性，是开发大规模MoS纳米片的一种有前景的方法。在此，我们展示了一种在不同衬底（如平坦的SiO/Si、预图案化的SiO和导电衬底（TaN））上合成大规模水平和垂直排列的MoS的有效方法，这有利于各种直接的过渡金属二硫属化物的生产。特别是，我们通过改变生长区构型和工艺步骤，展示了对CVD优化的精确控制，以获得高质量的MoS层。我们证明，通过在CVD反应器内部生长区中S与MoO前驱体位置的局部变化而导致的构型变化的影响是导致形成不同取向MoS的关键因素。最后，我们通过拉曼光谱、扫描电子显微镜（SEM）、光致发光（PL）和X射线光电子能谱（XPS）等不同表征手段展示了生长的MoS的层质量和物理性质。这些实验结果为在许多不同构型（即衬底可变性）或图案（即垂直或平面排列）中保形重塑AP-CVD生长的MoS提供了一条强有力的途径，具有应用于柔性电子学、光电子学、存储器到能量存储设备的潜力。
