The luminescence properties of transition metal d³ ions have exhibited widespread application potential in optical thermometry, while the emissive characteristics of self-trapped excitons in lead-free metal halides have garnered significant attention in the field of optoelectronics. Nonetheless, a comprehensive investigation into the temperature-dependent luminescence features of d³ ion-doped lead-free metal halides remains an area demanding in-depth exploration. Herein, we report on the visible and near-infrared (NIR) photoluminescence of 5d³ Re⁴⁺ doped vacancy-ordered metal halide Cs₂ZrCl₆ synthesized via hydrothermal methods. The undoped Cs₂ZrCl₆ host exhibits broad band self-trapped exciton (STE) emission. PL measurements reveal that its anti-thermal quenching PL under 270 nm excitation is predominantly due to the enhancement of the hot absorption band tail. Upon UV excitation, Re⁴⁺ doped Cs₂ZrCl₆ concurrently emits STE emission and features a narrow-band NIR emission at 730 nm with vibronic sideband details from the ReCl₆²⁻ octahedra, alongside a narrow-band emission at 1340 nm. By harnessing the luminescence intensity ratio (LIR) technique, combined with the anti-thermal quenching of STEs and the thermal quenching of Re⁴⁺ emission, optical thermometry with a relative sensitivity as high as 2.76% K⁻¹ is achieved. Our findings suggest that Re⁴⁺-doped Cs₂ZrCl₆ represents a multifunctional optoelectronic platform with promising applications in NIR illumination and temperature sensing.

中文翻译：

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用于光学测温和近红外照明应用的 Re4+ 掺杂 Cs2ZrCl6 的增强型 VIS-NIR 发射


过渡金属d ³ 离子的发光特性在光学测温中表现出广泛的应用潜力，而无铅金属卤化物中自俘获激子的发射特性在光电子领域引起了广泛的关注。尽管如此，对d ³ 离子掺杂的无铅金属卤化物的温度依赖性发光特性的全面研究仍然是一个需要深入探索的领域。在此，我们报道了 5d ³ Re ⁴⁺ 掺杂空位有序金属卤化物 Cs ₂ ZrCl ₆ 通过水热法合成。未掺杂的 Cs ₂ ZrCl ₆ 主体表现出宽带自俘获激子 (STE) 发射。 PL测量表明，其在270 nm激发下的抗热猝灭PL主要是由于热吸收带尾部的增强。在 UV 激发下，Re ⁴⁺ 掺杂的 Cs ₂ ZrCl ₆ 同时发射 STE 发射，并具有 730 nm 的窄带 NIR 发射，并具有来自ReCl ₆ ²⁻ 八面体，在 1340 nm 处有窄带发射。利用发光强度比（LIR）技术，结合STE的抗热猝灭和Re ⁴⁺ 发射的热猝灭，光学测温相对灵敏度高达2.76% K ⁻¹ 已实现。我们的研究结果表明，Re ⁴⁺ 掺杂的 Cs ₂ ZrCl ₆ 代表了一种多功能光电平台，在近红外照明和温度传感方面具有广阔的应用前景。