采用坩埚下降法技术,选用CdO∶WO3∶MnO摩尔比为100∶100∶0.5的化学组分配比,在约60℃固液界面温度梯度与0.05 mm/h生长速度条件下,成功地生长出Φ25 mm×100 mm Mn2+掺杂CdWO4(Mn2+:CWO)单晶。观测了晶体未退火、经空气和O2退火...采用坩埚下降法技术,选用CdO∶WO3∶MnO摩尔比为100∶100∶0.5的化学组分配比,在约60℃固液界面温度梯度与0.05 mm/h生长速度条件下,成功地生长出Φ25 mm×100 mm Mn2+掺杂CdWO4(Mn2+:CWO)单晶。观测了晶体未退火、经空气和O2退火处理后的的吸收、激发和发射光谱。结果表明,在Mn2+:CWO晶体的发射光谱中观测到发光中心约为591 nm的橙色荧光带,它归属于Mn2+的4T1g→6A1g能级跃迁。从Mn2+的橙色发射可以推断Mn2+取代晶体中Cd2+的格位,位于八面体晶场中。从其光谱特性,确定了Mn2+的能级结构。退火处理增强了激发和发射峰的强度,并且O2退火比空气退火的效果更显著。展开更多
A series of single-composition emission-tunable CdWO4：Eu^3＋ uniform size nanorods were synthesized by polyvinylpyrrolidone（PVP） assisted hydrothermal process. The products were measured by powder X-ray diffraction...A series of single-composition emission-tunable CdWO4：Eu^3＋ uniform size nanorods were synthesized by polyvinylpyrrolidone（PVP） assisted hydrothermal process. The products were measured by powder X-ray diffraction（PXRD）, scanning electron microscopy（SEM）, transmission electron microscopy（TEM）, photoluminescence, and fluorescent decay test. The results showed that reaction time, temperature, p H values and Eu^3＋ doped concentration played important roles in determining the morphologies and photoluminescent properties. And we also investigated its use in Ga N LED, warm-white-light could be obtained by the combination of the bright blue light originated from the charge transfer transition in the tungstate groups and the near UV light from LED chip with the red emission from 4f-4f transition of Eu^3＋, respectively. By properly tuning the doping concentration of Eu^3＋, chromaticity coordinates（0.30 0.22） could be achieved under the 380 nm excitation and its color rendering index was 80.6. So it has potential application in warm-WLED and replacing the commercial YAG：Ce phosphor which absence of red band emission.展开更多
基金Project supported by the National Natural Science Foundation of China(21301115)the Shanghai University Innovation Fund(sdcx2012005)Funding Scheme for Training Young Teachers in Colleges and Universities(ZZSD12025)
文摘A series of single-composition emission-tunable CdWO4：Eu^3＋ uniform size nanorods were synthesized by polyvinylpyrrolidone（PVP） assisted hydrothermal process. The products were measured by powder X-ray diffraction（PXRD）, scanning electron microscopy（SEM）, transmission electron microscopy（TEM）, photoluminescence, and fluorescent decay test. The results showed that reaction time, temperature, p H values and Eu^3＋ doped concentration played important roles in determining the morphologies and photoluminescent properties. And we also investigated its use in Ga N LED, warm-white-light could be obtained by the combination of the bright blue light originated from the charge transfer transition in the tungstate groups and the near UV light from LED chip with the red emission from 4f-4f transition of Eu^3＋, respectively. By properly tuning the doping concentration of Eu^3＋, chromaticity coordinates（0.30 0.22） could be achieved under the 380 nm excitation and its color rendering index was 80.6. So it has potential application in warm-WLED and replacing the commercial YAG：Ce phosphor which absence of red band emission.
