Efficient phosphors for mercury-free fluorescent lamps

[I]调查了将从双光子准分子获得的172 nm波长的VUV光转换为可见光的高效磷光体。2001年，我们研究了稳定氧化物，特别是稀土正磷酸盐中量子切割过程的可行性。结果表明，稀土离子高能激发态的非辐射弛豫和稀土离子间的能量转移可以降低量子切割的几率。然而，从Pr ~（3+）或Tm ~（3+）到Gd ~（3+）的能量转移导致在312 nm处的有效Gd ~（3+）发光线，其可以应用于灯，其激活光活性催化。这种现象是由Pr 3+或Tm 3+的简单电子构型引起的，它们具有两个4f电子或空穴。[II]在2002年，我们研究了通过从主体到活化剂离子的能量转移而激发的材料。（1）在YAlO_3：Eu ~（3+）中用Gd取代Y，在172 nm光激发下，效率提高了30%。这个显著的效果 ...更多信息 s从由Gd取代的主晶体的吸收边的红移。我们还开发了一种合成方法，以提供高效率的单相材料，该方法使用θ氧化铝作为起始原料，烧成温度高达15000。(2)In SrTiO_3：Pr ~（3+），Al是一种高效的红色荧光粉，其能量来源于Pr ~（3+）的束缚激子，研究表明基质的基本吸收带与Pr ~（3+）的4f-5d吸收带之间的能量重叠与发光效率有关。[III]通过阴极射线激发绝缘材料的粗糙粉末层发现了明亮的暖白色发射。这种发射出现在阈值电子束电流之上，并且强度随着束电流密度的增加而急剧增加。在25 kV电子束激发下，束径为0.3mm时，获得的最低阈值电流为0.02mA。如果阈值能够进一步降低，这种发射可能是新的无汞光源的候选者。少

[I]Efficient phosphors were surveyed to convert VUV light of 172nm wavelength obtained from Xe excimers to visible light. In 2001, we investigated feasibility of quantum cutting processes in stable oxides, specifically rare-earth orthophosphates. The results showed that nonradiatative relaxation from a high-energy excited level of a rare-earth ion and energy transfer between rare-earth ions in the UV region can reduce the probability of the quantum cutting. However, energy transfer from Pr3+ or Tm3+ to Gd3+ leads to efficient Gd3+ luminescence line at 312nm, which can be applied to lamps, which activate photoactive catalysis. This phenomena result from simple electronic configurations of Pr3+ or Tm3+, which have two 4f electrons or holes.[II]In 2002, we investigated materials excited by energy transfer from a host to an activator ion.(1)Substitution of Y by Gd in red-emitting YAIO3:Eu3+ gives rise to 30% increase in efficiency under 172nm light excitation. This remarkable effect result … More s from a red shift of the absorption edge of the host crystal by Gd substitution. We also developed a synthesis method to provide a single-phase material of high efficiency, which uses theta alumina as a starting material and firing temperature as high as 15000.(2)In efficient red phosphor, SrTiO3:Pr3+, Al, energy is provided from the bound exciton to Pr3+.This work has shown that energy overlap between the fundamental absorption band of the host and 4f-5d absorption band of Pr3+ is correlated with the luminescence efficiency.[III]Bright warm-white emission was discovered by cathode-ray excitation of rugged powder layers of insulater materials. This emission appears above the threshold electron-beam current and drastically increases in intensity with an increase in the beam-current density. The lowest threshold so far obtained is 0.02mA under 25kV electron excitation with a beam diameter of about 0.3mm. This emission may be a candidate of new non-mercury light source if the threshold can be further decreased. Less