Infinite Organic Solid-Solution Semiconductors with Continuous Evolution in Film Morphology, Crystalline Lattice and Electrical Properties

Constructing a solid solution is an effective strategy for regulating the properties of composite organic semiconductors. However, there presents significant challenges in fabrication and understanding of organic solid-solution semiconductors. In this study, infinite solid-solution semiconductors are successfully achieved by integrating rod-like organic molecules, thereby overcoming the limitations of current organic composite semiconductors. Within these solid solutions, one type of molecule are incorporated into the crystalline lattice of another through random substitution. The continuous evolution in film morphology, crystalline lattice parameters and physical properties are observed as component ratios vary, accompanying with changes in the growth behavior of films. Molecular-level intercalation is evidenced by Davydov splitting, photoluminescence spectroscopy, and optical absorption analyses. Moreover, the continuous variation in ionization potential is demonstrated through organic Schottky diodes. This advancement in organic solid solutions can not only satisfy diverse requirements for device fabrication but also facilitate novel designs in device architecture.