Structural engineering of BaWO4/CsPbX3/CsPb2X5 (X = Cl, Br, I) heterostructures towards ultrastable and tunable photoluminescence
Peng Liu, Yan Xu, Bohan Li, Yuchi Zhang, Hongzhou Lian, Jun Lin
Abstract
Construction of lead halide perovskite nanocrystals (LHP NCs) heterostructures is essential to obtain highly stable photoluminescence and expand their applications. Herein, a novel self-assembly strategy combining with a solvent-free thermal-assisted synthesis and a water-triggered reaction is developed to subsequently grow BaWO4/CsPbX3/CsPb2X5 (X = Cl, Br, I) heterostructures at low nucleation temperature with high crystallinity. The as-obtained ternary BaWO4/CsPbX3/CsPb2X5 (X = Cl, Br, I) heterostructures exhibit remarkably enhanced panchromatic emission and ultrastable luminescence ascribing to the low-defect growth based on lattice matching. Stable white light-emitting diodes (WLEDs) have been constructed with a high correlated color temperature (CCT) of 7225 K and luminous efficiency of 74.4 lm·W−1. Ln3+-doped BaWO4/CsPbX3/CsPb2X5 (Ln3+ = Eu3+, Tb3+, Dy3+, Sm3+, Yb3+/Er3+) nanocomposites are further designed with excitation-dependent photoluminescence and thermochromic properties, making them excellent candidates for high-level anti-counterfeiting and encryption. This work offers a green and universal approach in assembling CsPbX3 (X = Cl, Br, I) on lattice-matched tungstate with adjustable panchromatic emission for versatile optical applications.