Highly Luminescent Earth‐Benign Organometallic Manganese Halide Crystals with Ultrahigh Thermal Stability of Emission from 4 to 623 K

Abstract

vigorously studied over the past decades since the emergence of blue LED. [1] A myriad of efficient phosphors including yellow emissive Y 3 Al 5 O 12 :Ce 3+ (YAG:Ce 3+ ), blue emissive BaMgAl 10 O 17 :Eu 2+ (BAM:Eu 2+ ), green emissive Si 6−z Al z O z N 8−z :Eu 2+ (0 < z ≤ 4.2) (β-Sialon:Eu 2+ ), and red emissive Y 2 O 3 :Eu 3+ have been commercialized and applied in indoor and outdoor illumination, traffic lights, and display backlight to name but a few. Nonetheless, the high junction temperature of LED chips (usually ≥150 °C) leads to nonradiative relaxation and diminish the luminescence efficiency of phosphors. [2] This phenomenon is widely known as thermal quenching (TQ) and is the main issue in further improving the performance and application of PC-LEDs. [2][3][4] The effect is expected to be even more severe in emerging micro-LED applications due to the proximity of phosphors with the LEDs. Furthermore, in traditional phosphors, the emission comes from atomic electron transition of earth scarce rare-earth elements, and the mining process of these elements poses a great threat to the environment and the health of the miners. [5] Therefore, the development of earth abundant emitters with high efficiency and TQ-resistant is urgent.

Water‐Stable 0D Hybrid Manganese Halides with Adjustable Crystal Structure and Emission Color

“…[ 36,37 ] In addition, low‐dimensional hybrid manganese halides are also applied as X‐ray scintillators with high light yields exceeding 80 000 photons MeV −1 , which exhibits advanced application prospects in radiation monitoring, non‐destructive flaw inspection, medical imaging, etc. [ 34,40,41 ]…”

“…Among these LDMH luminescent materials, manganese(II) based halides display strong luminescence with multiple superiorities of high PLQY, long lifetime from microsecond to millisecond, low-cost, and non-toxicity. [33][34][35] Structurally speaking, low-dimensional hybrid manganese halides contain [MnX 4 ] 2− tetrahedron or [MX 6 ] 4− octahedron as basic building units and luminescent centers. [34,36] Generally, the [MnX 4 ] 2− tetrahedron and [MX 6 ] 4− octahedron based halides display intrinsic narrow green and red light emissions from the d-d electron transition of d 5 configuration, respectively.…”

“…[33][34][35] Structurally speaking, low-dimensional hybrid manganese halides contain [MnX 4 ] 2− tetrahedron or [MX 6 ] 4− octahedron as basic building units and luminescent centers. [34,36] Generally, the [MnX 4 ] 2− tetrahedron and [MX 6 ] 4− octahedron based halides display intrinsic narrow green and red light emissions from the d-d electron transition of d 5 configuration, respectively. The emitting energy is related to the crystal field strength and split energy states of coordination environments based on Tanabe-Sugano (T-S) diagram.…”

“…[36,37] In addition, low-dimensional hybrid manganese halides are also applied as X-ray scintillators with high light yields exceeding 80 000 photons MeV −1 , which exhibits advanced application prospects in radiation monitoring, nondestructive flaw inspection, medical imaging, etc. [34,40,41] The excellent luminescent property and broad application fields of low-dimensional hybrid manganese halides intrigued further in-depth synthetic mechanism at molecular level to realize rational structural design, which is also greatly desirable for subsequent exploring of high-performance luminescence performance. Herein, it is noteworthy that the structural construction of low-dimensional hybrid manganese halides is overwhelmingly dependent on the aimless self-assembly of organic cations and manganese salts in solution at present.…”