Broadband NIR-emitting Te cluster-doped glass for smart light source towards night-vision and NIR spectroscopy applications

Abstract

Broadband near-infrared (NIR)-emitting materials are crucial components of the next generation of smart NIR light sources based on blue light-emitting diodes (LEDs). Here, we report a Te cluster-doped borate glass, which exhibits ultra-broadband emission around 980 nm with a full-width at half-maximum (FWHM) of 306 nm under blue light excitation. We propose adjustments of glass chemistry and processing condition as a means for topo-chemical tailoring of the NIR photoemission characteristics in such materials. Through implementing strongly reducing conditions during glass melting, Te clusters with broad NIR photoluminescence can be generated and stabilized once the melt is vitrified to the glassy state. Tunability of the NIR emission peak over the wavelength range of 904 to 1026 nm is possible in this way, allowing for fine adjustments of spectral properties relative to the stretching vibrations of common chemical bonds, for example, in water, proteins, and fats. This potentially enables high sensitivity in NIR spectroscopy. We further demonstrate potential application of glass-converted LEDs in night vision.

Net Gain at the Near‐Infrared from CsPbBr3 Quantum Dots Sensitized Nd3+‐activated Tellurite Glass Under Solar Excitation

“…Tan et al demonstrated that tellurium cluster‐doped glasses effectively excited by a blue LED can be used as the phosphor for NIR pc‐LEDs. [ 22 ] Their NIR LED showed a promising photoelectric efficiency (≈21.2% at 100 mA), but the precise control of the charge state of tellurium is demanding and poses a great challenge. In comparison, our NIR LED is superior in the compact structure, and offers a large scope for selecting the specific excitation channels at one's request.…”

“…Generally, NIR phosphors consist of a luminescent ion (dopant) and a host material, such as trivalent (Pr 3+ , Nd 3+ , Er 3+ , Tm 3+ , and Yb 3+ ) [13][14][15][16] or divalent (Eu 2+ ) lanthanide ions (Ln 3+ ), [5,17] transition (Cr 3+ , Cr 4+ , Ni 2+ , Fe 3+ ) [4,[18][19][20][21] or heavy metal (Te, Bi) [12,22] ions doped inorganic crystals and glasses embedded with specially designed nano-or micro-crystals. Currently, the two mostly studied NIR emitting ions of Nd 3+ and Cr 3+ based on intraconfigurational 4f-4f and 3d-3d transitions, respectively, suffer from weak (and narrow-band in case of Nd 3+ ) absorption strength restricted by the Laporte selection rule.…”

Main Group Elements Activated Near‐Infrared Photonic Materials

“…Subsequently, Tan et al achieved NIR luminescence in Tedoped borate glass for the first time by optimizing the content of modifiers in borate glass and introducing C. [118] The composition of glasses are (mol%)49B 27 Al NMR spectra. d-f) Schematic presentation for the modulation of the Te clusters by altering the topological cages.…”

Thermally stable and tunable broadband near-infrared emission from NIR-I to NIR-II in Bi-doped germanate glass for smart light sources

“…Glasses, together with transparent ceramics, have recently been investigated as practical alternatives to the organic polymer binders for pc-NIR LED devices due to their excellent thermal stability, high durability, and module structure with easy assembly and disassembly. 22,32 Highly transparent glass has no scattering centers and the incident light can travel longer lengths and thus has a higher probability of being absorbed when it encounters NIR active centers; however, the research is still mainly focused on the NIR-I region. Fortunately, we note that Bi within various glass systems can exhibit tunable and broadband luminescence in almost the entire NIR region (800-1800 nm), and shows strong and wide absorption in the UV-Vis and NIR region.…”