Shilpa C K, Jasira S V, Veena V P, Aardhra M, Nissamudeen K M
School of Pure and Applied Physics, Kannur University, Payyanur Campus, Edat, Kannur, Kerala, 670327, India.
J Fluoresc. 2025 Jul;35(7):5273-5281. doi: 10.1007/s10895-024-03909-0. Epub 2024 Aug 27.
Co-doping strategy is done if the emission from the activator is relatively low with existing excitation energy. Thus, to enrich the emission from an activator, the sensitizer like Bi is co-doped onto the host and this intermediator transfers its emission energy to the activator. Prior to the study, no investigations had been conducted, marking the foundational exploration of the sensitizer effect within the rare earth-doped SrCeO matrix aimed at enhancing luminescence properties. The current study focuses on the innovation of single-phase robust white phosphors, SrCeO: 2wt% Sm: xBi (x = 0 wt%, 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%) to coat near UV LED chips for high CRI wLED applications. The novel perovskites were synthesized using a low-temperature fuel excess gel combustion method, utilizing citric acid as the fuel and ammonium nitrate as an extra oxidizer. Upon co-doping SrCeO: 2wt% Sm with bismuth, the impact of changing sensitizer concentration on both the development of crystalline phases, morphology, elemental composition, band gap energy, and the luminescent properties of ceramic powders were explored through X-ray diffraction, FE-SEM, Energy dispersive spectra, UV-visible absorption spectra, and photoluminescence characterization methods. The experimental results revealed the orthorhombic single-phase formation of SrCeO: 2wt% Sm: xBiperovskites yielding high crystallinity and luminescence maximum at critical sensitizer concentration 1 wt% Bi. Also, the bright white light emission of all the perovskites was confirmed using the CIE color diagram. Thus, nano-perovskite SrCeSmO: 1wt% Bi acts as an inevitable direct phosphor coating the near UV chip in LEDs, which can be a great revolution in energy savings applications.
如果激活剂在现有激发能量下的发射相对较低,就会采用共掺杂策略。因此,为了增强激活剂的发射,像铋这样的敏化剂会被共掺杂到主体中,这种中间体将其发射能量转移给激活剂。在这项研究之前,尚未进行过相关研究,这标志着在稀土掺杂的SrCeO基质中对敏化剂效应进行基础探索,以增强发光性能。当前的研究聚焦于创新单相坚固白色荧光粉SrCeO: 2wt% Sm: xBi(x = 0 wt%、0.5 wt%、1 wt%、1.5 wt%、2 wt%),用于涂覆近紫外LED芯片,以实现高显色指数的白光发光二极管应用。采用低温燃料过量凝胶燃烧法合成了新型钙钛矿,以柠檬酸为燃料,硝酸铵为额外氧化剂。在SrCeO: 2wt% Sm中掺杂铋后,通过X射线衍射、场发射扫描电子显微镜、能谱、紫外可见吸收光谱和光致发光表征方法,探索了敏化剂浓度变化对陶瓷粉末的晶相发展、形态、元素组成、带隙能量和发光性能的影响。实验结果表明,SrCeO: 2wt% Sm: xBi钙钛矿形成了正交单相,在临界敏化剂浓度1 wt% Bi时具有高结晶度和最大发光强度。此外,使用CIE色度图确认了所有钙钛矿的明亮白光发射。因此,纳米钙钛矿SrCeSmO: 1wt% Bi作为一种不可避免的直接荧光粉,可涂覆在LED的近紫外芯片上,这在节能应用方面可能是一场重大变革。