Ya Chen,Xiaojuan Liang,Jianping Liu,Suqin Chen,Weidong Xiang
All-inorganic CsPbX3 perovskite nanocrystals (PeNCs) are being investigated intensively as a promising optoelectronic material. However, the issues of its intrinsic instability and toxicity restrict their commercial applications. Herein, we proposed a facile method to improve the stability of CsPbX3PeNCs by encapsulating in a superhydrophobic polymer poly(styrene–ethylene–butylene–styrene) (SEBS) matrix. The blue–green–red emission CsPbX3@SEBS (X = Cl/Br, Br, Br/I) composite films exhibit high stability against moisture and are thermally stable. It is worth noticing that the photoluminescent quantum yield (PLQY) of the CsPbBrI2@SEBS composite film can reach 60%. The SEBS polymer matrix not only protects the PeNCs from contact with the ambient surroundings but also inhibits the escape of lead ions. Notably, the CsPbX3@SEBS flexible films were used as color conversion materials to construct a light-emitting diode (LED) device, and the device exhibits a wide color gamut (113% of the National Television System Committee (NTSC)). This work demonstrates the potential of using CsPbX3@SEBS flexible films as highly efficient color conversion materials for white LED and backlight displays.
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).