Near-infrared (NIR) mechanoluminescence (ML) materials have been of great interest within biological tissues due to their biocompatibility and suitability for biostress imaging. However, the reported NIR MLs have predominantly featured narrowband ML emissions, which may limit their further applications. In this study, a novel broadband NIR ML material of Lu₃Ga_4.88O₁₂:0.12Cr³⁺ (FWHM > 120 nm) is reported. By substituting Al³⁺ for Ga³⁺, the local crystal field strength and the defect concentration are reasonably regulated, which further improves the NIR ML (650-1000 nm) intensity of Cr³⁺ ion by 475%. In addition, by compounding polydimethylsiloxane with this phosphor, the obtained Cr³⁺ NIR ML film can penetrate 10 mm pork tissues quite well, indicating potential applications for stress distribution optical imaging within living organisms. Expectingly, broadband NIR ML from Cr³⁺ ions can be obtained by further solid-solution multiple lattice sites substitution, which may provide a new approach to improve the performance of NIR ML materials towards expanded biological applications.

近红外（NIR）机械发光（ML）材料由于其生物相容性和生物应力成像的适用性而在生物组织中引起了极大的兴趣。然而，所报道的近红外 ML 主要具有窄带 ML 发射特征，这可能会限制其进一步应用。在这项研究中，报道了一种新型宽带近红外ML材料Lu ₃ Ga _4.88 O ₁₂ :0.12Cr ³⁺ (FWHM > 120 nm)。 通过用Al ³⁺替代Ga ³⁺，合理调节局部晶体场强和缺陷浓度，进一步提高了 Cr ^{3+的NIR ML（650-1000 nm）强度}离子减少 475%。此外，通过将聚二甲基硅氧烷与该荧光粉复合，所获得的Cr ³⁺  NIR ML薄膜可以很好地穿透10 mm的猪肉组织，这表明在生物体内应力分布光学成像方面具有潜在的应用前景。预计，可以通过进一步固溶体多晶格位点取代来获得来自Cr ³⁺离子的宽带NIR ML ，这可能为提高NIR ML材料的性能以扩展生物应用提供新的方法。