Broadband near-infrared (NIR) light sources hold promise forsome important NIR spectroscopy applications such as nightvision, plant growths, optical communications, remote sensing,biomedical imaging and other noninvas...Broadband near-infrared (NIR) light sources hold promise forsome important NIR spectroscopy applications such as nightvision, plant growths, optical communications, remote sensing,biomedical imaging and other noninvasive and nondestructivedetections [1–4]. Recently, the phosphors-converted NIR lightemittingdiodes (LEDs) based on “blue LED chips + broadbandNIR phosphors” are widely developed for next-generation costeffectiveNIR light sources. In this respect, the performance ofNIR phosphors directly determines the overall quality of phosphors-converted NIR LEDs. Therefore, the development ofefficient, blue LED-excitable, broadband NIR phosphors ishighly demanded. Current research works on broadband NIRphosphors mainly focus on Cr^(3+) and Eu^(2+) activated inorganiccompounds, but Cr3+-activated NIR phosphors might showpotential carcinogenic risk owing to the presence of Cr6+ byproduct,while Eu2+-activated NIR phosphors still suffer fromlow luminescence efficiency [5]. As a result, new alternativeenvironmentally-friendly broadband NIR phosphors areurgently needed. In recent years, lead-free metal halides havearoused widespread interest for lighting and displays because oftheir fascinating visible emissions [6–8];however, their NIRluminescence has not received enough attention. Moreover, thecurrently developed NIR-emitting lead-free metal halides exhibitsome disadvantages including low emission efficiency and theirlimited excitation wavelengths in the ultraviolet (UV) range.Until now, finding an efficient, blue LED-pumped, broadbandNIR-emitting lead-free metal halide remains a formidablechallenge.展开更多
文摘Broadband near-infrared (NIR) light sources hold promise forsome important NIR spectroscopy applications such as nightvision, plant growths, optical communications, remote sensing,biomedical imaging and other noninvasive and nondestructivedetections [1–4]. Recently, the phosphors-converted NIR lightemittingdiodes (LEDs) based on “blue LED chips + broadbandNIR phosphors” are widely developed for next-generation costeffectiveNIR light sources. In this respect, the performance ofNIR phosphors directly determines the overall quality of phosphors-converted NIR LEDs. Therefore, the development ofefficient, blue LED-excitable, broadband NIR phosphors ishighly demanded. Current research works on broadband NIRphosphors mainly focus on Cr^(3+) and Eu^(2+) activated inorganiccompounds, but Cr3+-activated NIR phosphors might showpotential carcinogenic risk owing to the presence of Cr6+ byproduct,while Eu2+-activated NIR phosphors still suffer fromlow luminescence efficiency [5]. As a result, new alternativeenvironmentally-friendly broadband NIR phosphors areurgently needed. In recent years, lead-free metal halides havearoused widespread interest for lighting and displays because oftheir fascinating visible emissions [6–8];however, their NIRluminescence has not received enough attention. Moreover, thecurrently developed NIR-emitting lead-free metal halides exhibitsome disadvantages including low emission efficiency and theirlimited excitation wavelengths in the ultraviolet (UV) range.Until now, finding an efficient, blue LED-pumped, broadbandNIR-emitting lead-free metal halide remains a formidablechallenge.
