Supramolecular Ordered Organic Thin Films for Nonlinear Optical and Optoelectronic Applications

For second‐order nonlinear optics, a supramolecularly ordered non‐centrosymmetric structure is required. Additionally, well‐ordered organic semiconducting thin films possess superior electronic properties compared to their amorphous counterparts. Herein, we firstly highlight that the design of nonlinear molecules and their functionalization for good molecular orientation (e.g., H‐bonding) is an important method in which to induce supramolecular ordering during subsequent growth. Secondly, we demonstrate a range of growth strategies (e.g., oblique‐incidence molecular beam deposition, hot‐wall deposition) for the growth of molecularly ordered thin films. Thirdly, we discuss various organic supramolecularly ordered material systems (4‐[trans(pyridin‐4‐ylvinyl)] benzoic acid, 5‐bromo‐5′‐formyl‐2,2′‐bithiophene‐4‐nitrophenyl hydrazone, tris(8‐hydroxyquinoline) aluminum) and observe the effects of molecular orientation on their nonlinear optical and optoelectronic properties. Supramolecular self‐assembly of organic molecules is essential for second‐order nonlinear optics and highly desirable for organic electronics. A range of molecular‐design and growth strategies for achieving ordered organic thin films (see Figure, width = 20 nm) is outlined, and their nonlinear optical and optoelectronic properties are described.