RESUMEN
Two-dimensional (2D) hybrid layered perovskites (HLPs) have attracted extensive attention due to their excellent optoelectronic properties. Herein, we successfully prepared high-quality Mn-doped BDACdBr4 (BDA = NH2(CH2)4NH2, butylene diammonium) HLP single crystals (SCs). The incorporation of Mn2+ ions modulates the electronic band structure of BDACdBr4 perovskites and tailors the energy transfer process of excited states. A near-unity photoluminescence (PL) quantum yield of 96% from the Mn2+ emission at 608 nm is achieved. Excitation wavelength-dependent spectroscopic characterizations help to clarify the energy transfer mechanism of Mn-doped BDACdBr4, in which competing PL from the 3Eg â 1A1g transition of Cd2+ and the 4T1(G) â 6A1(S) transition of Mn2+ dopants is observed. Temperature-dependent PL spectroscopic characterizations indicate that the efficient energy transfer from BDACdBr4 perovskite host to Mn2+ dopants requires thermal activation to overcome a potential barrier. This work provides new insight into the photophysics and optical properties of 2D HLPs, especially the influence of Mn2+ doping on competing energy transfer in hybrid luminescent materials.
RESUMEN
A2BIBIIIX6 double perovskites are promising materials due to their outstanding photoelectronic properties and excellent stability in the environment. Herein, we synthesized Mn2+:Cs2NaTbCl6 with dual emission through a solvothermal method for the first time. Mn2+:Cs2NaTbCl6 double perovskites exhibit excellent environmental stability and high photoluminescence quantum yields (PLQYs). The Cs2NaTbCl6 was successfully doped with Mn2+ in two modes: at Mn-feeding concentrations below 1%, Mn2+ first tend to insert into the interstitial void, but if the Mn-feeding concentration exceeds 1%, Mn2+ will further substitute Na+ site of the Cs2NaTbCl6 lattice and thus both two doping modes coexist. After Mn2+ doping, efficient energy transfer from the 5D4 level of Tb3+ ions to the 4T1 level of Mn2+ ions occurs, resulting in tunable dual emission from the Tb3+5D4 â 7FJ=6,5,4,3 transition and Mn2+4T1 â 6A1 transition. Further, LED based on the Mn2+:Cs2NaTbCl6 double perovskites exhibits excellent performance and stability. This work demonstrates a strategy to achieve novel lanthanide-based double perovskites with potential applications in photonics.