Organic Phosphorescent Hopper‐Shaped Microstructures

Hopper‐shaped microcrystals, an unusual type of crystal with a large specific surface area, are promising for use in catalysis, drug delivery, and gas sensors. In contrast to well‐studied inorganic hopper‐shaped crystals, organic phosphorescent concave hopper‐shaped microstructures are rarely reported. This study reports the synthesis of two types of organic stepped indented hopper‐shaped microstructures with efficient room temperature phosphorescence (RTP) using a liquid phase self‐assembly strategy. The formation mechanism is attributed to the interfacial instability induced by the concentration gradient and selective etching. Compared with flat microstructures, the stepped indented hopper‐like RTP microstructures exhibit high sensitivity to oxygen. This work also demonstrates that packing the photochromic material into the concave hopper “vessel” effectively controls the switch of phosphorescence from energy transfer, expanding the potential applications of phosphorescent materials. An organic hexagonal microstructure with step‐indented hopper‐shaped morphology based on RTP materials is achieved under the synergistic effect of Oswald ripening and interfacial instability. Placing the photochromic material in this standing miniature RTP hopper “vessel” can effectively control the switch of phosphorescence through energy transfer.