Zeng Liwei, Zhong Jiyou, Lin Wenbin, Zhao Weiren
School of Physics and Optoelectronic Engineering, Guangdong University of Technology, Guangzhou 510006, China.
Guangdong Provincial Key Laboratory of Information Photonics Technology, Guangdong University of Technology, Guangzhou 510006, China.
Dalton Trans. 2022 Nov 8;51(43):16740-16747. doi: 10.1039/d2dt02971e.
Near-infrared (NIR) spectroscopy (700-1100 nm) based on a phosphor-converted light-emitting diode (pc-LED) has multi-functional applications in bio-imaging, night-vision, and food quality analysis, simulating the development of efficient and ultra-broadband NIR phosphors. Herein, a series of tunable and ultra-broadband NIR phosphor GaZnGeO:Cr was successfully produced by a [Zn-Ge] unit co-substituting a [Ga-Ga] unit in GaO:Cr. With the increasing amount of [Zn-Ge] incorporation, the emission peak can be tuned from 726 to 808 nm, and the maximum FWHM can be extended from 126 to 190 nm. However, the excitation peak position remained nearly unchanged in the blue light region, enabling this material to perfectly match the InGaN blue LED chip. Although the gradually enhanced electron-lattice coupling and low energy barrier for thermal quenching caused by this co-substitution lead to a decrease in the photoluminescence quantum yield (PLQY) and thermal stability, respectively, the absolute values of these two criteria can be well maintained. Finally, to evaluate the practical applications, prototype NIR pc-LEDs were fabricated using these materials combined with 450 nm LED chips. Under the same conditions, the NIR output power and photoelectronic conversion efficiency of these devices are superior to those fabricated using the well-known ScBO:Cr phosphor. These results demonstrate that this series of materials with tunable and ultra-broadband NIR emissions has great potential for NIR pc-LED applications.
基于磷光转换发光二极管（pc-LED）的近红外（NIR）光谱（700-1100纳米）在生物成像、夜视和食品质量分析中具有多功能应用，这推动了高效和超宽带近红外磷光体的发展。在此，通过[Zn-Ge]单元共取代GaO:Cr中的[Ga-Ga]单元，成功制备了一系列可调谐且超宽带的近红外磷光体GaZnGeO:Cr。随着[Zn-Ge]掺入量的增加，发射峰可从726纳米调谐至808纳米，最大半高宽（FWHM）可从126纳米扩展至190纳米。然而，激发峰位置在蓝光区域几乎保持不变，使得这种材料能够与InGaN蓝光LED芯片完美匹配。尽管这种共取代导致的电子-晶格耦合逐渐增强以及热猝灭的低能垒分别导致光致发光量子产率（PLQY）和热稳定性下降，但这两个指标的绝对值仍能得到较好维持。最后，为了评估实际应用，使用这些材料与450纳米LED芯片相结合制备了近红外pc-LED原型。在相同条件下，这些器件的近红外输出功率和光电转换效率优于使用著名的ScBO:Cr磷光体制备的器件。这些结果表明，这一系列具有可调谐和超宽带近红外发射的材料在近红外pc-LED应用中具有巨大潜力。
