phosphors prepared by a solid-phase reaction in air. Under 362 nm excitation, the luminescence results showed that a broad blue Eu2+ emission band with a peak at 437 nm appears unexpectedly in addition to the usual sharp orange-red emission of Eu3+. The mixed-valence fact of Eu2+/Eu3+ was further confirmed by X-ray photoelectron spectra and time-resolved spectroscopy techniques. The underlying mechanism
开发具有高质量白光的固态照明的可行方案仍然是一项重大挑战。特别地,已经对具有单组分白光发射的可调发光进行了广泛研究,以改善
磷光体转换的白光发光二极管(pc-WLED)
磷光体的发光性能。在这项工作中,首先在空气中通过固相反应制备的Eu活化
磷灰石型Ba 5(PO 4)3 Cl荧光粉中发现了一种新的自发还原现象。在362 nm激发下,发光结果表明,除了通常的尖锐的
橘红色发射的Eu 3+之外,还意外地出现了峰值为437 nm的宽的Eu 2+蓝色发射带。Eu的混合价事实X射线光电子能谱和时间分辨光谱技术进一步证实了2+ / Eu 3+。潜在的机制可以通过电荷补偿模型来解释。因此,通过引入Ca 2+,详细研究了Ba 5- y Ca y(PO 4)3 Cl:Eu 2+ / Eu 3+中发光的局部晶体现场工程控制。发现Ba 2+的Ca 2+取代将导致Eu 3+发射的新分裂峰以及Eu 2+的红移和蓝移分别发