我們正處在利用光電元件中單層二維材料的彎曲程度去得到更有效的光-物質交互作用的浪頭上。與原本的塊材材料相比，二維材料的量子侷限效應使我們可以改變原子薄膜的型態已引發一些令人矚目的物理化學現象。舉例來說，把這些二維材料堆疊起來可得到異質結構、伸縮可得皺紋結構、捲起來可得一維結構、或者包裹起來得到零維結構。不同維度的凡得瓦力結構對應到了不同的能隙以及載子的移動率，如皺紋結構能夠透過內部反射產生大量的電子；一維奈米捲的奈米結構可以限制電子的移動方向、不受外部的擾動。更特別的是，二維奈米片捲成一維捲軸狀所導致的彎曲會對電子和光的作用產生限制，光子的限制使材料產生相干性的雷射作用；螺旋狀的一維結構定位了激子並使其產生對偏振的光敏度。與扁平的結構相比，這種準一維結構的出色光捕獲能力提高了幾乎一個數量級的光催化效率，對這些奈米結構形態的操控可以使薄膜產生不同的空間梯度，改變其激子的生成機制和相應的載子壽命。石墨烯，TMD材料（例如 MoS2、WS2、ReS2）等這些能夠重複的機械應變的材料是很好用於做成不同形狀結構，二維TMD的另一個重要特徵是它們能夠產生原子級別精確度的異質結構，這些異質結構產生層跟層之間的激子並增強了光載子的解離作用，與高性能的量子點（如CdSe-ZnS, Perovskites）結合後，可以在介面上形成第二類型的能帶對齊。應變導致的異質TMD材料可以在H2和O2生成過程中充當有效的化學催化劑，更進一步來說，WS2/MoS2的異質卷軸結構是一種很高效的光催化劑材料，我們可以因此在異質介面上產生有效的光-物質交互作用以發現奇特的物理現象，最後可以在現實應用上開發出一種高效能且可靈活彎曲的裝置;We are on the cusp of utilizing the flexural strength of the monolayer 2D films in optoelectronic devices to emphasize strong light-matter interaction at the molecular level. Manipulating the morphology of the atomically thin layer of 2D materials introduces some striking physio-chemical phenomena compared to their bulk as well as sheet counterpart due to the strong in-plane quantum confinement effect. These 2D materials can be stacked up into heterostructure, buckled up to form a wrinkle structure, rolled up into 1D, or wrapped up into the 0D structure. Different dimensional van der Waals structure tunes the energy bandgap and hence the corresponding carrier mobility. A wrinkle pattern structure is capable of generating an ample number of electrons by multiple internal reflections whereas unidirectional nanoscroll structure can confine the motion of the electron in the 1D axis without having any external perturbation. In particular, the rolling of 2D TMD nanosheets into 1D scrolls induces bending strain and produces a confinement for electronic and photonic interactions. Photonic confinement in these nanocavities stimulates coherent lasing actions. The helical 1D structure predominantly localizes the excitons in the circumferential direction giving rise to polarized photosensitivity. The excellent phototrapping quality of this quasi-1D structure helps to enhance photocatalytic efficiency by almost an order of magnitude compared to the flat counterpart. The manipulation of the morphology of these nano-structures generates a spatial strain gradient throughout the film which modulates their exciton generation mechanism and the corresponding carrier lifetime. Graphene, TMD materials (eg. MoS2, WS2, ReS2) being able to persist mechanical strain is preferably used to form deformed structures. Another important feature of 2D TMDs is their ability to produce atomically precise heterojunctions. The resulting heterojunctions produces interlayer excitons and enhances photocarrier dissociation. Upon hybridizing them with high yield quantum dots, (eg. CdSe-ZnS, Perovskites) type–II band alignments are formed at the heterostructured (2D-0D) interface. Strain induced heterogeneous TMD material act as an efficient photoelectrochemical catalyst in H2 and O2 generation process. Specifically, WS2/MoS2 heterojunction scroll structure act as an efficient photocatalyst material. Our approach thus enables strong light-matter interaction at 2D material heterojunctions for discovering exotic physical phenomena and developing novel high-performance flexible devices toward realistic applications.
