Research progress in cyan and blue phosphors

Abstract

In recent years, the research and development of new white LEDs have attracted extensive attention. Whether the new LED has a higher color rendering index and can simulate natural sunlight...

Evidence and Practical Applications of Site Occupancy Theory (SOT) of Eu3+ in Scheelite Compounds

“…In the process of returning from the luminous level to the ground state, the energy is mainly dissipated in the form of light and heat energies, thus achieving the luminescence process. 67,80,81 In this article, compounds with scheelite structures are taken as an example to prove the feasibility and correctness of using site occupancy theory (SOT) to prove the site occupation. KEu(WO 4 ) 2 , KY(WO 4 ) 2 and Na 5 Eu(WO 4 ) 4 , Na 5 Y(WO 4 ) 4 with the same crystal structure and cationic coordination number were synthesized using a traditional high-temperature solid-phase method.…”

“…Rare earth ions absorb foreign energy and then undergo extra-nuclear electrons transition from the ground state to the excitation state; then, through thermal vibration and site vibration in the excitation state, part of the energy is lost in the form of heat or other potential energy and then to the luminous level. In the process of returning from the luminous level to the ground state, the energy is mainly dissipated in the form of light and heat energies, thus achieving the luminescence process. ,, …”

Engineering linkers to regulate solid-state emission of spirodifluorene-based conjugated porous polymers for white light-emitting devices

“…However, there are some pro-blems in the preparation of LED devices, such as film-related difficulties, process complexity, and the need for precious metals or rare earth elements that make it impossible to produce sustainably. [9][10][11][12][13][14] For organic materials, 15,16 the luminous efficiency for small-molecule organic materials is greatly reduced due to the inherent aggregation-caused quenching effect. 17 The desired luminescence effect for traditional polymer materials requires chemical doping to achieve different ratios of organic fluorescent groups, which often needs a lot of time for pre-designing the structure and regulating the proportion of the dopant, causing a high cost of time.…”

Polymer‐Encapsulated Halide Perovskite Color Converters to Overcome Blue Overshoot and Cyan Gap of White Light‐Emitting Diodes

“…Ultraviolet (UV) excited luminescence characteristics of Eu ions, Ce ions, and other ions in different host lattice (aluminate, silicate, phosphate, and borate) matrices have been explored for the cyan‐emissive photophores. [ 25–30 ] For example, Liang et al. reported cyan‐emitting Ce 3+ ‐doped Ca 2 YHf 2 Al 3 O 12 (CYHAO) garnet phosphor with bright broadband cyan emission (λ em = 493 nm; bandwidth = 100 nm) together with a photoluminescence quantum yield (PL QY) of 89.5% under 408 nm excitation.…”