Search

Phosphor-converted near-infrared light-emitting diodes based on garnet structure as the host for chromium incorporation are promising light sources for modern compact devices and are also an excellent alternative to traditional tungsten lamps.

Portable near-infrared (NIR) light sources are in high demand for applications in spectroscopy, night vision, bioimaging, and many others. Typical phosphor designs feature isolated Cr3+ ion centers, and it is challenging to design broadband NIR phosphors based on Cr3+-Cr3+ pairs. Here, we explore the solid-solution series SrAl11.88-xGaxO19:0.12Cr3+ (x = 0, 2, 4, 6, 8, 10, and 12) as phosphors featuring Cr3+-Cr3+ pairs and evaluate structure-property relations within the series. We establish the incorporation of Ga within the magentoplumbite-type structure at five distinct crystallographic sites and evaluate the effect of this incorporation on the Cr3+-Cr3+ ion pair proximity. Electron paramagnetic measurements reveal the presence of both isolated Cr3+ and Cr3+-Cr3+ pairs, resulting in NIR luminescence at approximately 650-1050 nm. Unexpectedly, the origin of broadband NIR luminescence with a peak within the range 740-820 nm is related to the Cr3+-Cr3+ ion pair. We demonstrate the application of the SrAl5.88Ga6O19:0.12Cr3+ phosphor, which possesses an internal quantum efficiency of ∼85%, a radiant flux of ∼95 mW, and zero thermal quenching up to 500 K. This work provides a further understanding of spectral shifts in phosphor solid solutions and in particular the application of the magentoplumbites as promising next-generation NIR phosphor host systems.

Narrowing the size of near-infrared (NIR) spectrometers has gained substantial interest among researchers in both scientific and nonscientific communities due to the inherent usage in the nondestru...

In this paper, a dual diode model of solar powered photovoltaic is explored to improve the efficiency of generation transforming structures of solar photovoltaic force. The double diode model is simple and straightforward to produce and offers greater precision which allows a more precise prediction of the presentation of photovoltaic structures. The survey depends on the reading results and it is for this reason that the MATLAB device is used. The reconstructions are completed by the fluctuation of the different limits of the model such as the oriented solar radiation, the temperature, the value of the parasitic screen, the ideality factor of the diode and the quantity of solar cells also associated which serve to accumulate the photovoltaic cluster. An obvious demonstration will be conducted to analyze the impacts of these details on the productivity curve and resistance/voltage performance of the PV cell for explicit models. Characterizing another frontier \(\left( \alpha \right)\), a practically best solution is suppressed for the I-V curve of the photovoltaic model, which is better than the conventional outlier model due to its high computational efficiency in the constant supply of photovoltaic meadow.

Near-infrared (NIR) phosphors are fascinating materials that have numerous applications in diverse fields. In this study, a series of La3Ga5GeO14:Cr3+ phosphors, which was incorporated with Sn4+, B...

The near-infrared (NIR) light source is desirable for real-time nondestructive examination applications, which include the analysis of foodstuffs, health monitoring, iris recognition, and infrared cameras. The emission spectra of such an infrared light source should also be as broad as possible for effective performance, in view of the fact that the broad absorption and reflection of light by the organic elements present in foodstuffs and human health fall in the blue and NIR regions of the electromagnetic spectrum, respectively. In this letter, a blue light-emitting diode (LED) excitable super broadband NIR phosphor light source is developed with a high fwhm of 330 nm and radiant flux of 18.2 mW for the first time. The observation of super-broad-band luminescence from two distinct luminescence centers is studied and evidenced by electron paramagnetic resonance, X-ray absorption near-edge structure, steady-state luminescence, and time-resolved luminescence at ambient and high-pressure environments. Finall...