a) E gap was determined from the intersection of the EQE edge and the local EQE maximum; b) V oc was calculated from the measured J-V curves; c) V oc rad was calculated from FTPS and EL measurements; d) EQE EL is the EL quantum efficiency of the fabricated devices; e) Exp. ΔE 3 is calculated with the Equation (ΔE 3 = −kTln(EQE EL )).

Optical multiplexing impacts widely in photonics, life science, biomedicine and engineering. Despite intensive efforts, current technology is limited by a longstanding “multiplexing ceiling” from existing optical materials. Here we engineered a novel class of polyyne-based materials for optical super-multiplexing. 20 distinct Raman frequencies are achieved as “Carbon rainbow” through rational engineering of conjugation length, bond-selective isotope doping and end-capping substitution of polyynes. With further probe functionalization, we demonstrated unprecedented 10-color organelle imaging in single living cell with high specificity, sensitivity, and photo-stability. Moreover, optical data storage and identification are realized by combinatorial barcoding, yielding the largest number of distinct spectral barcodes to date. Therefore, these versatile polyynes hold great promises in live-cell imaging and sorting, high-throughput diagnostics and screening, and information technology.

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X-rays are widely used in probing inside information nondestructively, enabling broad applications in the medical radiography and electronic industries. X-ray imaging based on emerging lead halide perovskite scintillators has received extensive attention recently. However, the strong self-absorption, relatively low light yield and lead toxicity of these perovskites restrict their practical applications. Here, we report a series of nontoxic double-perovskite scintillators of Cs 2 Ag 0.6 Na 0.4 In 1-y Bi y Cl 6. By controlling the content of the heavy atom Bi 3+ , the X-ray absorption coefficient, radiative emission efficiency, light yield and light decay were manipulated to maximise the scintillator performance. A light yield of up to 39,000 ± 7000 photons/MeV for Cs 2 Ag 0.6 Na 0.4 In 0.85 Bi 0.15 Cl 6 was obtained, which is much higher than that for the previously reported lead halide perovskite colloidal CsPbBr 3 (21,000 photons/MeV). The large Stokes shift between the radioluminescence (RL) and absorption spectra benefiting from self-trapped excitons (STEs) led to a negligible selfabsorption effect. Given the high light output and fast light decay of this scintillator, static X-ray imaging was attained under an extremely low dose of ∼1 μGy air , and dynamic X-ray imaging of finger bending without a ghosting effect was demonstrated under a low-dose rate of 47.2 μGy air s −1. After thermal treatment at 85°C for 50 h followed by X-ray irradiation for 50 h in ambient air, the scintillator performance in terms of the RL intensity and X-ray image quality remained almost unchanged. Our results shed light on exploring highly competitive scintillators beyond the scope of lead halide perovskites, not only for avoiding toxicity but also for better performance.

No abstract