Inverse opal photonic crystal stabilized CsPbX3 perovskite quantum dots and their application in white LED

Although the perovskite quantum dots (PQDs) have great application prospects, the poor stability of PQDs limits their commercial development. Inspired by the previous works, which employ the hydrophobic polymers and micro-nano structures to encapsulate and protect the PQDs, non-wetting inverse opal photonic crystals (IOPCs) are introduced to improve the stability of the PQDs in this work. In the designed composite, the PQDs are embedded in the porous structures of the IOPCs. The inner large surface area provides enough space for the dispersion of the PQDs, thus preventing the luminescence quenching induced by agglomeration. Meanwhile, the non-wetting of the IOPCs' outer surface can prevent the PQDs from contacting with water in the natural environment. Under the combined function of the above two protective effects, the luminescence stability of the prepared composite film was improved to more than four months. In addition, since the PQDs are inside the IOPCs, the luminescence properties of the PQDs can be regulated by matching the emission peak of the PQDs with the reflection peak of the IOPCs. A "sandwich" composite film composed of PQDs and IOPCs is also designed, which presents the application potential in white LED.