Chen Long, Zhong Jiyou
School of Physics and Optoelectronic Engineering, Guangdong University of Technology, Guangzhou 510006, China.
Guangdong Provincial Key Laboratory of Sensing Physics and System Integration Applications, Guangdong University of Technology, Guangzhou 510006, China.
ACS Appl Mater Interfaces. 2024 Aug 7;16(31):41119-41126. doi: 10.1021/acsami.4c06635. Epub 2024 Jul 29.
Broadband near-infrared (NIR) phosphors are crucial components of NIR phosphor-converted light-emitting diode (pc-LED) sources for various smart spectroscopy applications. However, developing an efficient, tunable, and inexpensive broadband NIR phosphor with sufficient spectral coverage remains a great challenge. In this work, a cubic phosphate KAlTi(PO) with highly structural rigidity was chosen as host material for Cr substitution to create an efficient NIR emission. Synthesizing this compound, the obtained material exhibits a broadband NIR emission covering 700-1200 nm with a peak wavelength ranging from 820 to 860 nm depending on the Cr substituting concentration. The Cr concentration optimized sample possesses a photoluminescence quantum yield (PLQY) of 76.4% with an emission peak centered at 857 nm and a full width at half-maximum () of 184 nm under 464 nm exaction, demonstrating an efficient and relatively long-wavelength NIR emission with wide spectral coverage. This broadband NIR emission is mainly derived from a single kind of emission center deduced from spectral analysis, luminescence dynamics, and first-principle calculations. Using this material, the fabricated NIR pc-LED device presents an excellent NIR output power and NIR photoelectric conversion efficiency, making this material attractive in practical applications of night-vision and bioimaging. Therefore, this work not only provides a broadband NIR material with superiorities of low cost, high efficiency, wide-range tunability, wide spectral coverage, and relatively long-wavelength NIR emission for spectroscopy applications but also highlights some clues to discover this kind of materials.
宽带近红外（NIR）磷光体是用于各种智能光谱应用的近红外磷光体转换发光二极管（pc-LED）光源的关键组件。然而，开发一种高效、可调谐且廉价的具有足够光谱覆盖范围的宽带近红外磷光体仍然是一个巨大的挑战。在这项工作中，选择具有高度结构刚性的立方磷酸盐KAlTi(PO)作为主体材料进行Cr取代，以产生高效的近红外发射。合成该化合物时，所获得的材料表现出覆盖700-1200nm的宽带近红外发射，其峰值波长根据Cr取代浓度在820至860nm范围内变化。Cr浓度优化后的样品在464nm激发下具有76.4%的光致发光量子产率（PLQY），发射峰位于857nm，半高宽（FWHM）为184nm，展示了具有宽光谱覆盖范围的高效且相对长波长的近红外发射。这种宽带近红外发射主要源自光谱分析、发光动力学和第一性原理计算推导得出的单一发射中心。使用这种材料制造的近红外pc-LED器件呈现出优异的近红外输出功率和近红外光电转换效率，使其在夜视和生物成像的实际应用中具有吸引力。因此，这项工作不仅为光谱应用提供了一种具有低成本、高效率、宽范围可调谐、宽光谱覆盖和相对长波长近红外发射等优势的宽带近红外材料，还突出了发现这类材料的一些线索。
