Preparation of freestanding and ultrastable CsPbX3 perovskite quantum dots/SEBS composite films for curved and flexible surfaces

All-inorganic CsPbX3 (X = Cl, Br, I) perovskite quantum dots (PQDs)/polymer composite films have been used widely in light-emitting devices. Most methods of fabricating CsPbX3 PQDs/polymer composite films cannot meet the diverse requirements of real applications, particularly with regard to depositing or transferring films on different substrate types, including non-planar surfaces. It is still a challenge to prepare freestanding CsPbX3 PQDs/polymer composite films and deposit them on various substrates (especially non-planar substrates). Here, we report a facile way to prepare freestanding CsPbX3 PQDs/poly(styrene-ethylene-butylene-styrene) (SEBS) composite films via an interfacial-confinement (IC) strategy. The as-obtained films were applicable to various substrates (even curved and flexible substrates) and exhibited excellent stability against various environments. These freestanding CsPbX3 PQDs/SEBS composite films could be patterned readily for anti-counterfeiting and information-encryption applications. They also could be employed as color-conversion materials for white light-emitting diodes (LEDs).