Highly Efficient Broadband Yellow Phosphor Based on Zero-Dimensional Tin Mixed-Halide Perovskite

Abstract

Organic-inorganic hybrid metal halide perovskites have emerged as a highly promising class of light emitters, which can be used as phosphors for optically pumped white light-emitting diodes (WLEDs). By controlling the structural dimensionality, metal halide perovskites can exhibit tunable narrow and broadband emissions from the free-exciton and self-trapped excited states, respectively. Here, we report a highly efficient broadband yellow light emitter based on zero-dimensional tin mixed-halide perovskite (CNHBr)SnBrI (x = 3). This rare-earth-free ionically bonded crystalline material possesses a perfect host-dopant structure, in which the light-emitting metal halide species (SnBrI, x = 3) are completely isolated from each other and embedded in the wide band gap organic matrix composed of CNHBr. The strongly Stokes-shifted broadband yellow emission that peaked at 582 nm from this phosphor, which is a result of excited state structural reorganization, has an extremely large full width at half-maximum of 126 nm and a high photoluminescence quantum efficiency of ∼85% at room temperature. UV-pumped WLEDs fabricated using this yellow emitter together with a commercial europium-doped barium magnesium aluminate blue phosphor (BaMgAlO:Eu) can exhibit high color rendering indexes of up to 85.

Lead‐Free Highly Efficient Blue‐Emitting Cs3Cu2I5 with 0D Electronic Structure

“…On the other hand, a large Stokes shift of ≈155 nm is similar to those of the 0D Sn‐based metal halide perovskites, implying that the PL mechanism cannot be explained simply by a direct band emission. Instead, the exciton self‐trapping or the excited‐state structural reorganization is possible mechanism …”

Intrinsic White‐Light‐Emitting Metal–Organic Frameworks with Structurally Deformable Secondary Building Units

“…[6][7][8][9][10][11][12] This promising class of white-light emitters is amenable to crystal engineering for further enhancing their photoluminescence properties. [13][14][15][16][17][18] However,the intrinsic moisture instability of lead perovskites has not been fully addressed. [19] Luminescent metal-organic frameworks (MOFs) are considered to be an ideal platform for single-phase white-light photoemitters,o wing to their capability to organize multiple photoemissive components into as ingle lattice.…”

Highly Emissive Self-Trapped Excitons in Fully Inorganic Zero-Dimensional Tin Halides

“…Thef irst examples with high QYs in excess of 50 % were demonstrated only recently:( C 4 N 2 H 14 Br) 4 SnBr 6 (QY = 95 % AE 5%)and (C 4 N 2 H 14 I) 4 SnI 6 (QY = 75 % AE 4%). [21] Both structures are constructed from disconnected [SnX 6 ] 4À octahedra, separated by large organic cations with ad istance of more than 1nmbetween Sn 2+ centers.Given the high PL QY of these hybrid materials and their novel approach towards exciton localization, herein we chose to pursue fully inorganic analogues such as Cs 4 SnBr 6 .W hile several studies have reported on the structure and basic properties of Cs 4 SnBr 6 ,n one have observed PL at RT. [22] Recently,c alculations have shown that the Cs 4 SnBr 6 phase should have aband gap of 3.37 eV.…”

“…Thef irst examples with high QYs in excess of 50 % were demonstrated only recently:( C 4 N 2 H 14 Br) 4 SnBr 6 (QY = 95 % AE 5%)and (C 4 N 2 H 14 I) 4 SnI 6 (QY = 75 % AE 4%). [21] Both structures are constructed from disconnected [SnX 6 ] 4À octahedra, separated by large organic cations with ad istance of more than 1nmbetween Sn 2+ centers.…”

“…In (C 4 N 2 H 14 X) 4 SnX 6 (X = Br/I), [21] the addition of iodide red-shifts both the excitation and STE emission spectra. Similarly,t he PL of Cs 4 SnX 6 shifts to 620 nm (orange emission) at aB r:Ir atio of ca.…”