Luminescent inorganic mixed borate phosphors materials for lighting

Abstract

The need of new materials with desirable optical properties has become important in recent years. In particular, a need has emerged for compounds having better luminescence properties in various practical applications. The introduction of rare earth ions as activators improves the luminescence properties of the compounds considerably. Boron is one of the most abundant elements in nature. It readily combines with almost all other elements. In combination with oxygen; it forms borates comprised of various anions such as BO33−, B2O54−, etc. Apart from these simple borates, several complex compositions exist involving mixed anions as well as double metal borates, due to the three‐fold, or four‐fold coordination of borate atoms. Borates intrinsically possesses characteristics that are advantageous for optical materials, which include a wide transparency range, large electronic band gap, good thermal and chemical stability, low preparative temperature, optical stability with good nonlinear characteristics, and an exceptionally high optical damage threshold. The unique crystal structure of borates determines their enhanced ultraviolet light transparency, good nonlinearity, and relatively high resistance against laser‐induced damage. Some of these complex borates have interesting luminescence properties that are covered in this review. These include double borates containing rare earths RM3(BO3)4, pentaborates LaMgB5O10, M3R2(BO3)4, where M is an alkaline earth, mixed anion borates such as aluminoborate SrAl2B2O7, silicate‐borates such as pekovite, SrB2Si2O8, haloborates, M2B5O9X, where M is an alkaline earth and X is a halogen, phosphate borates, and MBPO5, where M is an alkaline earth. Phosphors based on these compositions find use in various applications such as fluorescence lamps, colour TVs, plasma display panels, high‐intensity discharge lamps based on xenon, optically pumped solid‐state lasers, eye‐safe lasers, and X‐ray imaging.

Photoluminescence in Cerium-Doped Fluoride Borate Crystals

“…The study of borate systems is a research field developing at the intersection of crystal chemistry and materials science. Borates are promising compounds due to their chemical diversity and many areas of practical applications. − Phosphors based on these compounds are important for the dosimetry of ionizing radiation and personnel monitoring, and medical dosimetry, etc. , …”

Photoluminescence properties of Sr3Y2(BO3)4: Eu3+ phosphor codoped with Gd3+ and La3+ under ultraviolet excitation

“…There are many types of oxysalt that can be used as a phosphor matrix, including aluminate, borate, vanadate, tungstate, molybdate, etc. Among them, the borate matrix has been generally considered by researchers because of its characteristics of high luminescence efficiency, low preparation temperature, and good chemical stability [3] . Li et al [4] prepared the series of phosphors Eu 3+ and Dy 3+ doped alkaline earth borate.…”

Deciphering the Role of Gamma Ray Induced Radicals in the Thermoluminescence Process of a Neutral to Cool Daylight Emitting Sr1–xB4O7–Dyx Phosphor through Electron Paramagnetic Resonance (EPR) Spectroscopy

“…There has been a plethora of reports on rare earth (RE) activated borate matrices being proposed as inorganic phosphor materials for radiation dosimetry and luminescence application. − On one hand with relatively lower effective atomic number, borate based systems can mimic human tissue for dosimetry applications. On the other hand, due to their non-centrosymmetric structure, the materials show higher radiative yield for application in light industries.…”