Flexible All‐Inorganic Perovskite Photodetector with a Combined Soft‐Hard Layer Produced by Ligand Cross‐Linking

Although perovskite nanocrystals have attracted considerable interests as emerging semiconductors in optoelectronic devices, design and fabrication of a deformable structure with high stability and flexibility while meeting the charge transport requirements remain a huge challenge. Herein, a combined soft‐hard strategy is demonstrated to fabricate intrinsically flexible all‐inorganic perovskite layers for photodetection via ligand cross‐linking. Perfluorodecyltrichlorosilane (FDTS) is employed as the capping ligand and passivating agent bound to the CsPbBr(3) surface via Pb‐F and Br‐F interactions. The Si—Cl head groups of FDTS are hydrolyzed to produce Si—OH groups which subsequently condense to form the Si—O—Si network. The CsPbBr(3)@FDTS nanocrystals (NCs) are monodispersed cubes with an average particle size of 13.03 nm and exhibit excellent optical stability. Furthermore, the residual hydroxyl groups on the surface of the CsPbBr(3)@FDTS render the NCs tightly packed and cross‐linked to each other to form a dense and elastic CsPbBr(3)@FDTS film with soft and hard components. The photodetector based on the flexible CsPbBr(3)@FDTS film exhibits outstanding mechanical flexibility and robust stability after 5000 bending cycles.