Recent advances in 2D organic topological insulators: materials, properties, and realizations

Two-dimensional (2D) organic topological insulators (TIs) have emerged as a promising frontier in quantum materials research over the past decade, combining the structural versatility of organic frameworks with exotic topological states. Since the first organic TI predicted in 2013, organic TIs have grown into a large material family including metal-organic frameworks, covalent-organic frameworks and hydrogen-bonded organic frameworks. This review comprehensively summarizes the research progress of 2D organic TIs, including lattice models, theoretical predictions and experimental realizations of various materials. The discussion focuses on the challenges of synthesizing promising materials and characterizing the topological states, as well as the recent progress in overcoming these challenges. The findings summarized here provide valuable guidance for designing new topological materials, paving the way for their potential applications.