Data-Driven Approaches to Discover Luminescent Materials
Luminescent materials are important to the development of many technologies and industries. They can provide light in an array of different ways, ranging from LEDs to solar cells to biosensors. In order to discover new luminescent materials, data-driven methods can be applied to analyze the properties of existing materials.
Data-driven methods for discovering new luminescent materials
Data-driven methods have become an essential part of materials discovery. The field has grown rapidly in recent years and there are many applications to discover and optimize materials. However, data-driven approaches are still rare for the development of nanomaterials.
In particular, researchers have turned to data-driven techniques to overcome the bottleneck of finding new luminescent materials. Traditionally, luminescent materials were developed based on serendipitous discoveries and experiments. Moreover, their performance and spectral properties depend on the environmental conditions. Thus, a robust predictive model requires a lot of input data. Fortunately, automated workflows and algorithms are emerging that can help expand the material database.
Using data-driven methods, scientists can find new luminescent materials and optimize their fabrication process. For instance, researchers have used supervised learning techniques to model the power consumption of each pixel in an OLED. Similarly, a novel evanescent microwave microscope has been used to determine magnetic and structural properties of materials. Several optical measurement techniques have also been used to characterize optical properties.
Data-driven materials research involves a combination of physics, mathematics, and informatics. The quality of the data is a crucial component to constructing robust models.
Typical data-driven materials discovery processes include the generation of a data set, the generation of descriptors, and the construction and validation of models. Typically, the last step involves the synthesis and characterization of suggested compounds.
In addition, data-driven methods can be applied to guide the synthesis of inorganic solids. Examples of such techniques include reaction pathway prediction and convex hull stability. Although these techniques are not yet commonly utilized for the discovery of new materials, they have the potential to speed up the discovery process.
Finally, the discovery of new luminescent materials has been made possible by the use of artificial intelligence (AI) and high-throughput synthesis methods. Using machine learning algorithms, scientists have been able to discover and optimize several promising materials. Likewise, AI could be instrumental in accelerating the development of laser phosphors.
Optical materials doped with lanthanide activators
Lanthanide-doped upconversion nanoparticles (UCNPs) are a unique class of optical materials. They convert near infrared excitations into visible or ultraviolet photons. UCNPs have many potential applications. These include XEOL, multiplex detection, and imaging.
Upconversion nanoparticles contain a sensitizer and an activator. UCNPs have several benefits, including their low autofluorescence and greater tissue penetration depth. In addition, their associated optical properties are promising.
Unlike traditional bulk scintillators, UCNPs have the possibility of bypassing the concentration quenching effect and can thus be used for imaging. Furthermore, the number of dopants can be controlled by wet-chemical synthesis methods. This allows for heterogeneously doped core@multishell nanocrystals. The dopants are accurately distributed, which allows for fine tuning of the doping concentrations in each layer.
Various lanthanide ions can be doped in a UCNP. These ions show a high sensitivity to doping. For example, Tb3+ leads to an intense green emission, whereas Ce3+ emits UV radiation. A Ce3+ ion has a 6.2 eV energy gap and a 5d excited state. Its excitation frequency is tuned by a CaF2 host. Yb3+ increases the absorbance in the NIR and enhances upconversion luminescence.
Upconversion NSs are a type of NS that can be triggered by UV or X-ray photons. These NSs have three stages of conversion: ionic absorption, cross relaxation, and phonon relaxation. Each of these processes is followed by a transfer of energy from the neighbouring ions. Once the doping concentration reaches a threshold, the cross relaxation process occurs and the ionic absorption is bypassed.
UCNPs have the potential to develop new photonic devices and hybrid materials. Moreover, their multi-color luminescent materials upconversion emission is highly efficient in transparent colloids of lanthanide-doped NaYF4 nanocrystals. This enables fine-tuning of the nanoparticles.
Geopolymers with luminescence properties tailored into the structure
Geopolymers are the product of geochemical reactions that create a network of mineral molecules linked by covalent bonds. They are produced from industrial by-products and geological raw materials. Several commercial applications are available for geopolymers. Compared to conventional cementitious materials, geopolymers have a higher strength, durability, and water resistance. Moreover, their carbon footprint is significantly lower.
During the synthesis process, a range of parameters must be considered for the successful production of high performance geopolymers. The number of microcapillaries, the W/S ratio, and the density are some of the most important aspects. It is also crucial to consider the chemical properties of each raw material, the degree of mechanochemical grinding, and the proportions of each element.
Among the raw materials, fly ash is a source of silicon and silica. It is widely used in geopolymerization. However, it is usually low in calcium. Sodium silicate is often used as an alkaline activator. This is due to its reactive component that helps in calculating the amount of silicate solution.
One important element is Al2O3. Metakaolin is another common aluminosilicate material. High Al content results in a stronger geopolymer network.
Another important element is CaO. It is a crucial component in the evolution of geopolymers. Moreover, it helps strengthen the network and reduces its thermal conductivity. Various formulations are studied in research.
Geopolymerization is an innovative method to reuse industrial by-products. These materials are often discarded and accumulated in landfills. Thus, they can be reclaimed and reused for the purpose of manufacturing value-added products. In this way, the global community can benefit from reuse of waste materials.
The main advantage of geopolymers is their improved mechanical properties. Moreover, they possess an extraordinary chemical properties. Hence, they are promising alternatives to OPC.
Lanthanide ions
Luminescent materials are used in diverse applications. For instance, lanthanide ions have been used in lasers, television cathode ray tubes, and hybrid car components. They are also used in liquid crystals and as phosphors. Lanthanides have long-radiative lifetimes and high color purity. These properties have made them ideal for the development of luminescent metallopolymers.
In order to develop highly luminescent lanthanide-containing compounds, designers must consider the effects of charge transfer states. As a result, they must carefully control the quenching process and optimize sensitization efficiency. The energy levels and the kinetics of the charge-transfer processes are important in determining the resulting emission quantum yields.
Lanthanide(III) complexes have been widely studied for their properties. Among these properties, they have been found to exhibit effective luminescence when attached luminescent materials with organic ligands. This effect is primarily attributed to intramolecular energy transfer. However, direct excitation is ineffective. Therefore, the design of appropriate ligands is crucial to producing effective luminescence.
Many lanthanide(III) complexes have shown photosensitized luminescence. One of the main reasons for this is the presence of a photoactive p-p* band of an organic ligand. Another factor that helps is the presence of an inter-LCT band. Interestingly, this LMCT band is formed due to steric strain in the organic ligands in the crystals. Despite the fact that these LMCT bands are present in lanthanide(III) complexes, effective energy transfer is not achieved.
To improve the energy level of a lanthanide(III) complex, researchers have developed a new molecular design strategy. It involves the design of an intra-LCT band and an inter-LCT band. In the solid state, the effectiveness of the LMCT band has been measured to be 61%. Moreover, this band has a significant effect on the energy transfer process between the ligand and the lanthanide(III) ion.
Emissive quantum dots (QDs) as an alternative to ceramic, inorganic phosphors
A new class of luminescent quantum dots (QDs) may offer an alternative to conventional ceramic, inorganic phosphors, and offer superior performance for a wide variety of applications. They have properties including high luminescence efficiency and non-radiative energy transfer. In addition, they can be processed at low costs and offer a broad range of color radiance.
A QD phosphor may be made by using a solid substrate, such as polyethylene, with a plurality of inorganic semiconductor cores arranged in a three-dimensional configuration. This structure is stable, and can be easily processed at low cost. When applied to a LED, the resulting light emitting diode has excellent light emission efficiency. It also provides excellent color rendering, with a CRI of 87.
The spectral purity of QDs is important in achieving a large color gamut. These particles are more durable and less susceptible to degradation than organic dyes. However, they face challenges related to electrical excitation. Hence, their performance may be improved with wider bandgap shells.
Quantum dots are a type of nanoparticles that are synthesized from organometallic precursors. Unlike conventional semiconductors, they are confined in three dimensions, and exhibit a unique optical downconversion effect. Their spectral purity can be used to generate a larger color gamut than that of HDTV.
Several methods have been developed to increase the efficiency of inorganic QD-LEDs. One technique is Forster energy transfer. Another method involves using a wide band gap organic thin film. Other techniques include phase separation and inkjet printing. Some of these approaches have been adapted to a variety of materials, and they can be applied to commercial devices.
Luminescent QDs can have a broad absorption spectrum, which is ideal for large-area lighting. Additionally, these particles may have size-tunable emission properties, which can improve their performance in lighting systems.
