本文使用稳态及时间分辨荧光光谱法对陶瓷相铁电材料SrxBa1-xNb2O6(SBN-x)及Cr3+掺杂的SrxBa1-xNb2O6 (SBN:Cr3+)的光生载流子的复合动力学进行了研究。带边激发条件下SBN-70非辐射复合过程在温度高于137 K时已快于辐射复合,说明SBN在765 nm处对应的发光中心极容易受到晶格振动影响,使激发态电子转而通过声子参与的无辐射跃迁回到基态。对于Cr3+离子掺杂的SBN-70,使用395 nm和480 nm激发得到发光中心的热激活能分别为Ea=380.9±61.0 meV和Ea=374.6±51.4 meV。发现了SBN低温下很强的光致荧光猝灭性质,其产生原因可能归属为样品对激发光的吸收造成的捕获电子态对发光的二次吸收。

The recombination dynamics of photo-excited carrier in ferroelectric ceramic SrxBa1-xNb2O6was studied by steady state and time-resolved photoluminescence spectroscopy.Under excitation by 395 nm in the absorption edge region,the non-radiative process became faster than the radiative process when the measurement temperatures of Sr0.7Ba0.3Nb2O6(SBN-70) ceramic above 137 K.This result means that the fluorescence(765 nm) in pure SBN can be easily quenched by phonon,resulting in the excited electrons de-excited to ground state mainly by phonon-assisted non-radiative process but not by photoluminescence.The thermal activation energy of the fluorescence center in Cr3+ion doped SBN is 380.9±61.0 meV and 374.6±51.4 meV,excited at 395 nm and 480 nm respectively.We have found a strong light-induced luminescence quenching effect in SBN ceramic under low temperature,which may be due to the reabsorption of the photo-induced electron trap states.