Highly efficient visible and near-infrared luminescence of Sb3+, Tm3+ co-doped Cs2NaYCl6 lead-free double perovskite and light emitting diodes

Efficient Near-Infrared Luminescence with Near-Unity Photoluminescence Quantum Yield in Erbium-Doped Double Perovskites Cs2NaYCl6 under Green Light Excitation

“…Generally, the cross-relaxation (C–R) between Er 3+ ions will lead to fluorescence quenching of many phosphors under heavy doping. , However, 25%Er 3+ -doped Cs 2 NaYCl 6 exhibits near-unity NIR PLQE (93 ± 2%) (NIR-II region ∼87%) under 520 nm excitation. Such a high PLQE of Er 3+ -doped Cs 2 NaYCl 6 under green light excitation stands out from the recently reported Er 3+ -doped metal halides (Table S3), which can be assigned to similar ionic activity between Y 3+ and Er 3+ , this allows for more Er 3+ ions to enter the host lattice and produce efficient NIR luminescence . To note that, the eruptive PLQE obtained in Er 3+ -doped Cs 2 NaYCl 6 should be attributed to the pronounced C–R between neighboring Er 3+ under heavy doping and coupled Er pair radiation transition, as observed in Cs 2 NaErCl 6 and Cs 2 NaBiCl 6 :Er 3+ . , In Figure b, there are two different paths of C–R in the heavy doped samples, that is 4 S 3/2 + 4 I 15/2 → 4 I 9/2 + 4 I 13/2 and 4 I 9/2 + 4 I 15/2 → 4 I 13/2 + 4 I 13/2 . − Hence, the electron population at the 4 S 3/2 level will be effectively depleted and transferred to the 4 I 9/2 and 4 I 13/2 levels through C–R.…”

“…Such a high PLQE of Er 3+doped Cs 2 NaYCl 6 under green light excitation stands out from the recently reported Er 3+ -doped metal halides (Table S3), which can be assigned to similar ionic activity between Y 3+ and Er 3+ , this allows for more Er 3+ ions to enter the host lattice and produce efficient NIR luminescence. 61 To note that, the eruptive PLQE obtained in Er 3+ -doped Cs 2 NaYCl 6 should be attributed to the pronounced C−R between neighboring Er 3+ under heavy doping and coupled Er pair radiation transition, as observed in Cs 2 NaErCl 6 and Cs 2 NaBiCl 6 :Er 3+ . 62,63 In Figure 5b, there are two different paths of C−R in the heavy doped samples, that is 4 S 3/2 + 4 I 15/2 → 4 I 9/2 + 4 I 13/2 and 4 I 9/2 + 4 I 15/2 → 4 I 13/2 + 4 I 13/2 .…”

Efficient near‐infrared emission in lanthanum ion doped double perovskite Cs2NaScCl6 via Cr3+ sensitization under visible light excitation

“…In addition, the different ionic activity of trivalent metal ions (e.g., Bi 3+ , In 3+ ) in DPs and Ln 3+ will severely restrict the insertion of Ln 3+ into the host lattice. 22,23 Therefore, it is urgent to find new strategies to enhance the NIR emission intensity of Ln 3+ in DPs under visible light excitation.…”

“…Parallelly, the large energy gap between emission energy of ns 2 metal ions or Mn 2+ and Ln 3+ will limit the ET efficiency from sensitizers to Ln 3+ ions, which will result in low PLQY of NIR emission in these codoped systems. In addition, the different ionic activity of trivalent metal ions (e.g., Bi 3+ , In 3+ ) in DPs and Ln 3+ will severely restrict the insertion of Ln 3+ into the host lattice 22,23 . Therefore, it is urgent to find new strategies to enhance the NIR emission intensity of Ln 3+ in DPs under visible light excitation.…”

Tunable dual-emission of Sb3+, Ho3+ Co-doped Cs2NaScCl6 single crystals for light-emitting diodes

“…For example, Shi et al co-doped Sb 3+ , Er 3+ , and Ho 3+ ions into Cs 2 NaInCl 6 with hydrothermal methods and achieved bright multicolor emission with narrow spectra and high PLQY [26]. Wang et al prepared Sb 3+ and Ln 3+ ion-doped Cs 2 NaYCl 6 SCs, which demonstrated bright tunable blue, red, and white light emission [27].…”