Persistent Trapping of Photo-generated Carriers in Colorless Anatase TiO2 Single Crystal
Persistent Trapping of Photo-generated Carriers in Colorless Anatase TiO2 Single Crystal
复制标题
无色锐钛矿型 TiO2 单晶中光生载流子的持续捕获
DOI：
10.1143/jpsj.81.124701
复制
发表时间：
2012
期刊：
影响因子：
--
通讯作者：
T. Kodaira
中科院分区：
文献类型：
--
作者：
T. Sekiya;Y. Takeda;H. Takeda;S. Ohya;T. Kodaira
在 100-30 K 下，紫外线 (UV) 光照射无色锐钛矿型二氧化钛单晶，在电子顺磁共振 (EPR) 光谱中出现六重态。六联体是由于光生空穴被捕获在与位于钛取代位点的杂质铝相邻的赤道氧中而产生的。取决于晶体取向的 EPR 测量表明，六重态 EPR 矩阵的主轴与晶轴略有不同。光诱导的六联体在黑暗中持续低于 80 K。尽管在 EPR 观察中没有检测到六联体，但在较低温度下在锐钛矿晶体中捕获光生空穴。在低于 50 K 的温度下，在紫外线照射下可观察到属于钛中捕获的光生电子的 EPR 单线态。该单线态在 30 K 以下的部分持久性表明光生电子持续被锐钛矿捕获。
Ultraviolet (UV) light irradiation to colorless anatase titanium dioxide single crystals at 100–30 K gives rise to the appearance of sextuplets in electron paramagnetic resonance (EPR) spectra. The sextuplets are due to photogenerated holes trapped in an equatorial oxygen adjacent to an impurity aluminum located at a substitutional site of titanium. The EPR measurement depending on crystalline orientation reveals that the principal axes of EPR matrices for the sextuplet are slightly different from the crystalline axes. Photoinduced sextuplets persist below 80 K in the dark. The trapping of photogenerated holes is performed in anatase crystals at lower temperatures even though the sextuplets are not detected in the EPR observation. Below 50 K, an EPR singlet assigned to a photogenerated electron trapped in titanium is observed under UV irradiation. The partial persistence of this singlet below 30 K indicates that photogenerated electrons are persistently trapped in anatase.