Synthesis and luminescent properties of ZnWO4: Cr3+ nanoparticles for NIR-II fluorescence imaging

Sharp-Line Near-Infrared Emission from Tetrahedron-Occupied Ni2+ in Ca2GeO4

“…Thus, the sample with the highest PLQY is the sample with the optimized concentration ( x = 0.01) (Figure b). It is well known that concentration quenching is a result of energy transfer between the adjacent activators when the intra-activators’ distance is smaller than the critical distance ( R c ), which could be calculated as follows , R normalc = 2 ( 3 V 4 π x c N ) 1 / 3 where V , N , and x c correspond to the cell unit volume (405.6 Å 3 ), number of host cations per unit cell (4), and optimized dopant concentration value (0.01), respectively. Thus, R c is calculated to be 26.85 Å.…”

“…Figure3b). It is well known that concentration quenching is a result of energy transfer between the adjacent activators when the intra-activators' distance is smaller than the critical distance (R c ), which could be calculated as follows24,25 z z where V, N, and x c correspond to the cell unit volume (405.6 Å 3 ), number of host cations per unit cell (4), and optimized dopant concentration value (0.01), respectively. Thus, R c is calculated to be 26.85 Å.The fluorescence decay curves of Ca 2 GeO 4 :xNi 2+ phosphors monitored at 1164 nm were collected at room temperature under a constant excitation wavelength of 620 nm.…”

Boosting broadband short-wave infrared emission to achieve near-unity quantum efficiency via bridging Cr3+–Ni2+ in spinel solid-solutions towards light-emitting diode applications

“…Short-wave infrared (SWIR) light holds great practical potential in night vision, non-invasive bioimaging, optical communication, health monitoring, and nondestructive testing and analysis, due to its unique electromagnetic wave features, such as invisibility to the human eye, tissue penetration, and intrinsic interaction with certain chemical groups. 1–12 Commercially available SWIR light sources have their own inevitable drawbacks. For example, semiconductor-based SWIR light-emitting diodes (LEDs) show an extremely narrow FWHM of their emission spectrum.…”

From Ancient Blue Pigment to Unconventional NIR Phosphor: A Thermal-Stable Near-Infrared I/II Broadband Emission from Ca1–xSrxCuSi4O10 Solid Solution

“…According to reports of Accorsi, Zhang, and Borisov, CaCuSi 4 O 10 is found to exhibit efficient and broadband NIR emission in the 800–1100 nm range, which has potential in multiple applications like nondestructive testing, night version, lasers, and solar concentrators. It is known that the spectral property (emission intensity, wavelength, bandwidth, kinetics, and thermal stability) of 3 d transition metal ions is closely related to the host material structure and the coordinated environment of their occupied sites, since the 3 d electrons are exposed to the external environment and experience significant electro-phonon coupling interaction. − One feasible and effective strategy to adjust the local structure is to change the compositions of the matrix through the solid-solution principle . Successful examples can be found in tuning optical properties by applying the substitution strategy on several Cr 3+ -activated NIR phosphors. − However, a spectral gap in the 900–1000 nm range usually exists in the reported Cr 3+ -activated NIR phosphors, i.e., both the quantum efficiency and thermal stability have a significant decrease as the emission wavelength extends to above 900 nm (Table ), which is definitely not conducive to spectral analysis and application.…”