Vacancy-ordered double perovskites, the variant of metal-halide perovskites, have excellent potential for use in optoelectronic and thermoelectric devices. A narrow region of forming the stable vacancy-ordered double perovskite Cs 2 PdBr 6 by the chemical potential calculation via the first principles method was reported. Perdew− Burke−Ernzerhof functionals were used to investigate the possible intrinsic defects and the corresponding formation energy of Cs 2 PdBr 6 . Under the Pd-rich condition, the V Br defect was spontaneously formed as it has the lowest formation energy among all donor defects. In contrast, the sample became a p-type conducting material with a high hole concentration under the Pd-poor condition. This indicates that the defect-induced decline of photoelectric properties of Cs 2 PdBr 6 can be alleviated by regulating the V Br defect alone. Finally, the Cs 2 PdBr 6 microcrystals were fabricated via hydrothermal synthesis. In addition, XRD, PL, and Raman spectroscopy were also performed on Cs 2 PdBr 6 powder to characterize the microstructure and optical properties of the compound; the results showed that V Br defects can be formed spontaneously, which is consistent with our theoretical calculations.

The electronic structure and optical properties of the two stable CsPbCl3 main phases (P4/mbm, Amm2) and the six most stable anion substitution structures under stress.

No abstract

All-inorganic cesium lead halide CsPbX3 (X=Cl, Br, I) perovskite quantum dots (PQDs) have shown promising potential in current Mini/Micro-LED display applications due to their excellent photoluminescence performance. However, lead ions in PQDs are easily to leak owing to the unstable structure of PQDs, which hinders their commercial applications. Herein, we adopt Rb+ ions co-doping strategy to regulate the doping characteristics of Mn2+ ions in CsPbCl3 PQDs. The synthesized CsPbCl3:(Rb+, Mn2+) PQDs possess enhanced photoluminescence quantum yield of 71.1% due to the reduction of intrinsic defect states and Mn-Mn or Mn-traps in co-doped PQDs. Moreover, the white light emission of CsPb(Cl/Br)3:(Rb+, Mn2+) PQDs is achieved by anion exchange reaction and the constructed WLED exhibits the CIE coordinate of (0.33, 0.29) and the CCT of 5497 K. Benefiting from the substitution strategy, these doped CsPbX3 PQDs can be widely used as fluorescence conversion materials for the construction of Mini/Micro-LED. Keywords: perovskite quantum dots; co-doping; photoluminescence quantum yield; WLED