Efficient deep-blue electroluminescence from Ce-based metal halide.

Rare earth ions with d-f transitions (Ce, Eu) have emerged as promising candidates for electroluminescence applications due to their abundant emission spectra, high light conversion efficiency, and excellent stability. However, directly injecting charge into 4f orbitals remains a significant challenge, resulting in unsatisfied external quantum efficiency and high operating voltage in rare earth light-emitting diodes. Herein, we propose a scheme to solve the difficulty by utilizing the energy transfer process.

Electrohydrodynamically Printed d-f Transition Cerium(III) Complex.

The d-f transition rare earth complexes have recently emerged as a promising candidate for display applications due to the parity-allowed transition, high photoluminescence quantum yield (PLQY), short excited lifetime, and tunable emissions. Besides, inkjet printing has been regarded as an important technique for realizing full-color display. However, inkjet-printed d-f transition rare earth complexes have not been investigated.

Vacuum-deposited RbCeI for deep-blue-light-emitting diodes.

Recently, perovskite light-emitting diodes (PeLEDs) have exhibited outstanding performance in next-generation high-definition display applications. However, compared with green and red PeLEDs, the development of efficient and stable blue PeLEDs to meet the requirement for a wide color gamut has been a challenge. Herein, we vacuum thermally deposited a film of the lead-free rare earth halide RbCeI, which shows deep blue emission with peaks at 427 nm and 468 nm.

Solution-Processed Hybrid Europium (II) Iodide Scintillator for Sensitive X-Ray Detection.

Lead halide perovskite nanocrystals have recently demonstrated great potential as x-ray scintillators, yet they still suffer toxicity issues, inferior light yield (LY) caused by severe self-absorption. Nontoxic bivalent europium ions (Eu) with intrinsically efficient and self-absorption-free transition are a prospective replacement for the toxic Pb. Here, we demonstrated solution-processed organic-inorganic hybrid halide BAEuI (BA denotes CHNH) single crystals for the first time.

Spectra stable deep-blue light-emitting diodes based on cryolite-like cerium(III) halides with nanosecond d-f emission.

Next-generation wide color gamut displays require the development of efficient and toxic-free light-emitting materials meeting the crucial Rec. 2020 standard. With the rapid progress of green and red perovskite light-emitting diodes (PeLEDs), blue PeLEDs remain a central challenge because of the undesirable color coordinates and poor spectra stability.