退火温度及气氛对Bi_4Ti_3O_(12)光致发光的影响

Effects of Annealing Temperature and Atmosphere on the Photoluminescence of Bi_4Ti_3O_(12) Nanomaterials

以Bi(NO3)3·5H2O和钛酸四丁酯[Ti(OC4H9)4]为原料,采用水热法制备了钛酸铋(Bi4Ti3O12,BiT)纳米材料。利用X线衍射(XRD)研究了产物的物相。结果表明,合成的产物为铋层状钙钛矿结构的BiT。N2气氛中不同退火温度下BiT纳米材料和BiT陶瓷的光致发光(PL)研究表明,420nm激发光激发下,470.6nm处的蓝-绿发光是因为氧空位捕获的电子和空穴形成的自束缚激子的辐射复合。而氧气氛中退火时发光强度减弱也表明蓝-绿发光与氧空位有关。

Bismuth titanate （Bi4Ti3O12, BiT） nanoplates were fabricated via hydrothermal method using Bi （NO3）3 · 5H2O and Ti（OC4 H9 ）4 as the starting materials. The phase of products were studied using X-ray diffrac- tion（XRD）, and the products were BiT nanoplates with bismuth-layered perovskite strucutue. After the products were annealed under N2 ambience,the PL investigation was carried out by the exciting light of 420 nm. The results showed that one blue-green photoluminescence band centered at around 470.6 nm was observed at room tempera- ture. The investigation of effects of the annealing temperatures on room-temperature visble emission showed that the annealing temperature or grain size play important roles for the intensities of blue-green light emission, and the oxy- gen vacancies should be responsible for this emission. Besides, when the products were annealed under oxygen ambi- ence, the weaker photoluminescence peak indicated that the blue-green photoluminescence is related to oxygen vacan-cies.