Sb-doped Rb2ZnCl4 for multiple optoelectronic applications

Lead-free halides, with the advantages of non-toxicity and high stability, have broad application prospects. Here, we studied the synthesis and luminescent properties of the Sb-doped Rb2ZnCl4 and explored their utilizations for white light-emitting diode (WLED) and X-ray detection. The as-synthesized Rb2-xZn1-xSbxCl4 single crystals exhibit bright red emission centered at 740 nm with a large full width at half maximum (FWHM) of 220 nm, and the maximum photoluminescence quantum yield (PLQY) is determined to be 59.7 % for the sample with x = 0.01. The assembled WLED achieves a high color rendering index (CRI) of 93.6 and a low correlated color temperature (CCT) of 3755 K. Under continuous X-ray irradiation for 600 s at a dose rate of 26.5 Gy min−1, the irradiation luminescence intensity of Rb1.99Zn0.99Sb0.01Cl4 did not decrease, indicating that the single crystal has a high tolerance to X-ray irradiation. Our work demonstrates that Zn halides are also a promising lead-free family for multiple optoelectronic applications.