The reduced symmetry in strong spin-orbit coupling materials such as transition metal ditellurides (TMDTs) gives rise to non-trivial topology, unique spin texture, and large charge-to-spin conversion efficiencies. Bilayer TMDTs are non-centrosymmetric and have unique topological properties compared to monolayer or trilayer, but a controllable way to prepare bilayer MoTe₂ crystal has not been achieved to date. Herein, we achieve the layer-by-layer growth of large-area bilayer and trilayer 1T′ MoTe₂ single crystals and centimetre-scale films by a two-stage chemical vapor deposition process. The as-grown bilayer MoTe₂ shows out-of-plane ferroelectric polarization, whereas the monolayer and trilayer crystals are non-polar. In addition, we observed large in-plane nonlinear Hall (NLH) effect for the bilayer and trilayer T_d phase MoTe₂ under time reversal-symmetric conditions, while these vanish for thicker layers. For a fixed input current, bilayer T_d MoTe₂ produces the largest second harmonic output voltage among the thicker crystals tested. Our work therefore highlights the importance of thickness-dependent Berry curvature effects in TMDTs that are underscored by the ability to grow thickness-precise layers.

过渡金属二碲化物 (TMDTs) 等强自旋轨道耦合材料的对称性降低导致了非平凡的拓扑结构、独特的自旋纹理和大的电荷到自旋转换效率。双层 TMDT 是非中心对称的，与单层或三层相比具有独特的拓扑特性，但迄今为止尚未实现制备双层 MoTe _{2晶体的可控方法。}在此，我们通过两阶段化学气相沉积工艺实现了大面积双层和三层1T'MoTe ₂单晶和厘米级薄膜的逐层生长。生长的双层 MoTe ₂显示平面外铁电极化，而单层和三层晶体是非极性的。此外，我们观察到在时间反转对称条件下双层和三层 T _d相 MoTe _{2的大面内非线性霍尔 (NLH) 效应，而对于较厚的层则这些效应消失。}对于固定的输入电流，双层 T _d MoTe ₂在测试的较厚晶体中产生最大的二次谐波输出电压。因此，我们的工作强调了 TMDT 中依赖于厚度的 Berry 曲率效应的重要性，这些效应通过生长厚度精确层的能力得到了强调。