Lead‐free halide double perovskites (DPs) have attracted much attention due to their potential applications in the field of near‐infrared (NIR) optoelectronics. However, regulating the NIR luminescence properties of such materials remains a challenge. In this study, it is found that Cs2AgInCl6:Cr3+ DPs exhibit a broad NIR emission under ultraviolet excitation, with a peak value of 980 nm. In the range of 9 GPa, the emission intensity increases significantly. As the pressure increases, a transition from broadband NIR emission to narrow‐line emission occurs, accompanied by a decrease in the full width at half maximum (FWHM) from 260 to 40 nm, attributed to increased local structural asymmetry and enhanced crystal field around Cr3+ ions. Ultrafast transient absorption experiments reveal the changes of energy transfer under pressure and the emergence of new radiation channels, demonstrating the dynamic evolution of emission characteristics under high pressure. The research results deepen the understanding of high pressure luminescence in Cr3⁺‐doped halide DPs, providing strategies for designing highly efficient NIR emitters in metal halide DPs.

中文翻译：

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Cr3+ 掺杂 Cs2AgInCl6 双钙钛矿中 NIR 发光的高压调制：超快能量转移的作用


无铅卤化物双钙钛矿 （DPs） 因其在近红外 （NIR） 光电子学领域的潜在应用而备受关注。然而，调节此类材料的 NIR 发光特性仍然是一个挑战。本研究发现 Cs2AgInCl6：Cr3+ DPs 在紫外激发下表现出较宽的 NIR 发射，峰值为 980 nm。在 9 GPa 范围内，发射强度显著增加。随着压力的增加，发生了从宽带 NIR 发射到窄线发射的转变，伴随着半峰全宽 （FWHM） 从 260 nm 减少到 40 nm，这归因于局部结构不对称性的增加和 Cr3+ 离子周围晶体场的增强。超快瞬态吸收实验揭示了压力下能量传递的变化和新辐射通道的出现，证明了高压下发射特性的动态演变。研究结果加深了对 Cr3 掺杂卤化物 DP 中高压发光的理解，为在金属卤化物 DP 中设计高效的 NIR 发射器提供了策略。