Scintillators are widely utilized for radiation detections in many fields, such as nondestructive inspection, medical imaging, and space exploration. Lead halide perovskite scintillators have recently received extensive research attention owing to their tunable emission wavelength, low detection limit, and ease of fabrication. However, the low light yields toward X-ray irradiation and the lead toxicity of these perovskites severely restricts their practical application. A novel lead-free halide is presented, namely Rb 2 CuBr 3 , as a scintillator with exceptionally high light yield. Rb 2 CuBr 3 exhibits a 1D crystal structure and enjoys strong carrier confinement and near-unity photoluminescence quantum yield (98.6%) in violet emission. The high photoluminescence quantum yield combined with negligible self-absorption from self-trapped exciton emission and strong X-ray absorption capability enables a record high light yield of ≈91056 photons per MeV among perovskite and relative scintillators. Overall, Rb 2 CuBr 3 provides nontoxicity, high radioluminescence intensity, and good stability, thus laying good foundations for potential application in low-dose radiography.
With its tunable bandgap and 385 nm violet emission, Rb2CuBr3 is a promising candidate for violet light-emitting diodes (LEDs). This work provides how Zn2+ doping enhances self-trapped exciton (STE) emission by modulating excited-state dynamics covered key factors in the STE luminescence dynamics. An anti-solvent synthesis strategy is developed to achieve Rb2CuBr3:xZn2+. The lowest defect formation energy (Eform) confirmed that Zn2+ occupation for the Cu⁺ site. X-ray absorption fine structure (XAFS) evidenced that the shortened bond lengths of with stronger Zn-Br has induced the lattice contraction and narrowed the band gap to favor the violet luminescence. Low temperature-dependent photoluminescence spectra (TDPL) with the time-resolved fluorescence spectra (TRF) have illuminated the whole STE dynamics. The increased exciton binding energy (Eb) by 37% effectively has suppressed exciton thermal dissociation to form classical STE process. However, the suppression ration of the non-radiative to radiative recombination rate (knr/kr) is 56.7%. Notably, the non-radiative recombination is depressed extensively. The optimized doping at Rb2CuBr3:0.3Zn2+ results in a maximum photoluminescence quantum yield (PLQY) of 70.6% and an approximate two-fold enhancement in PL intensity. This work provides how Zn2+ doping enhances STE emission by modulating excited-state dynamics. The fabricated violet LED integrates function of efficient curing, exhibiting broad application prospects.
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