Highly Luminescent and Patternable Block Copolymer Templated 3D Perovskite Films

Abstract

AbstractThe rapid development of lead halide perovskite light emitting diodes (PeLED) provides bright prospects for future lighting and display applications. However, the lack of efficient blue light emission, the insufficient device stability, and the shortage of convenient patterning methods greatly impede the development of PeLED applications. In this work, a feasible two‐step fabrication method combined with a block copolymer (BCP) template is introduced to fabricate high quality CH3NH3PbBrxCl3−x 3D perovskite film. The BCP‐templated CH3NH3PbBr3 film possesses a state‐of‐the‐art photoluminescence quantum yield (PLQY) of 62% in the champion sample (58% average PLQY) and an outstanding stability at room temperature. Using halide‐free lead acetate trihydrate as the lead source, the color of the photoluminescence can be tuned easily from green to blue by simply controlling the Cl/Br ratio in the second step. A sky‐blue emission is obtained from a CH3NH3PbBr1.5Cl1.5 perovskite film with a PLQY of 23 ± 2%. The two‐step fabrication approach can also enable straightforward patterning, as demonstrated with inkjet printing and Chinese calligraphy.