The zero-dimensional perovskite composite Cs₄PbBr₆/CsPbBr₃ has attracted significant attention for its remarkable photoluminescence (PL), which remains highly effective even in solid state. This work presents a detailed analysis of the steady-state and time-resolved PL (TRPL) behavior of millimeter-scale Cs₄PbBr₆/CsPbBr₃ crystals over a temperature range of 80 to 360 K, which covers exciton binding energy, phonon energy, and PL peak energy shifting with increasing temperature. According to the results, Cs₄PbBr₆/CsPbBr₃ exhibits high exciton binding energy and phonon energy, with calculated values of 358.7 and 94.8 meV, respectively. Specifically, when the temperature is below ∼235 K, thermal expansion dominates to influence the TRPL and peak energy, whereas electron-phonon interaction becomes the dominant factor as temperature rises from 235 to 325 K. It is found that Cs₄PbBr₆/CsPbBr₃ has a PL behavior similar to CsPbBr₃, and characterization and TRPL results demonstrate that nanometer-scale CsPbBr₃ crystals embed in the Cs₄PbBr₆ bulk matrix. Meanwhile, a white light-emitting diode (WLED) device based on Cs₄PbBr₆/CsPbBr₃ with luminous efficiency of 64.56 lm/W is fabricated, and its color coordinate is measured as (0.34, 0.31) under 20 mA, which is in close proximity to the standard white color coordinate. Moreover, the color gamut of the device is measured as 128.66% of the National Television Systems Committee (NTSC). The WLED electroluminescence (EL) spectra show high Correlated Color Temperature (CCT) stability for the working current varying from 5 to 100 mA, and after continuous operation for 12 h, the EL intensity decreases and stabilizes at ∼70% of the initial EL intensity. These findings suggest that Cs₄PbBr₆/CsPbBr₃ crystals are a promising candidate for WLEDs.

零维钙钛矿复合材料Cs ₄ PbBr ₆ /CsPbBr ₃因其出色的光致发光（PL）而引起了广泛关注，即使在固态下也保持高效。这项工作详细分析了毫米级 Cs ₄ PbBr ₆ /CsPbBr ₃晶体在 80 至 360 K 温度范围内的稳态和时间分辨 PL (TRPL) 行为，涵盖激子结合能、声子能和 PL 峰值能量随温度升高而变化。结果表明，Cs ₄ PbBr ₆ /CsPbBr ₃表现出较高的激子结合能和声子能，计算值分别为358.7和94.8 meV。具体来说，当温度低于~235 K时，热膨胀主导影响TRPL和峰值能量，而当温度从235 K升至325 K时，电子-声子相互作用成为主导因素。发现Cs 4 _PbBr 6 _/ CsPbBr_图3的PL行为与CsPbBr ₃类似，并且表征和TRPL结果表明纳米级CsPbBr ₃晶体嵌入Cs ₄ PbBr ₆体基质中。_{同时制作了基于Cs 4} PbBr ₆ /CsPbBr ₃的白光发光二极管(WLED)器件，其发光效率为64.56 lm/W，在20 mA下测得其色坐标为(0.34，0.31)，即非常接近标准白色坐标。此外，该设备的色域经国家电视系统委员会（NTSC）测量为128.66%。WLED 电致发光 (EL) 光谱在工作电流为 5 至 100 mA 的范围内表现出较高的相关色温 (CCT) 稳定性，连续工作 12 小时后，EL 强度下降并稳定在初始 EL 强度的 ∼70% 。这些发现表明 Cs ₄ PbBr ₆ /CsPbBr ₃晶体是 WLED 的有希望的候选者。