Structural and optical properties of KTa0.77Nb0.23O3 nanoplates synthesized by hydrothermal method.
Structural and optical properties of KTa0.77Nb0.23O3 nanoplates synthesized by hydrothermal method.
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DOI：
10.1016/j.jcis.2007.01.062
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发表时间：
2007-06
影响因子：
9.9
通讯作者：
Yongming Hu;H. Gu;Zhenglong Hu;Hao Wang
中科院分区：
文献类型：
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作者：
Yongming Hu;H. Gu;Zhenglong Hu;Hao Wang
以Ta2O5、Nb2O5和KOH为前驱体，在200℃条件下采用水热法制备了边缘尺寸约为100 nm、厚度约为10 nm的二维KTa0.77Nb0.23O3（KTN）纳米片。详细的结构研究表明，合成产物由大量的四边形单晶纳米片组成，具有立方钙钛矿结构，不含任何其他杂质相，生长方向为（011）。叠层断层可能是（011）板形成和发育的关键。不同波长激发的室温光致发光光谱在470 nm （2.63 eV）处有一个强发射峰，在423 nm （3.06 eV）和505 nm （2.46 eV）处有两个弱发射峰。局域激子的电子-空穴复合应该是423和470 nm光发射的原因。KTN纳米片的室温拉曼光谱显示，其振动模式频率略低于KTN块状材料，散射曲线更加扩散和放大，这可能是由于晶体结构缺陷（如层错）引起的。
Two-dimensional KTa0.77Nb0.23O3(KTN) nanoplates with edge sizes of about 100 nm and thickness of about 10 nm have been fabricated by hydrothermal method at 200 °C using Ta2O5, Nb2O5, and KOH served as the precursors. Detailed structural studies indicate that the synthesized products are made up of large quantity single crystalline nanoplates with quadrilateral shape, which have a cubic perovskite structure without any other impurity phase and (011) growth direction. The stacking faults may be the key in the formation and growth of the (011) plate. Room temperature photoluminescence spectra excited at different wavelengths exhibit a strong emission band centered at 470 nm (2.63 eV) as well as two weak emission peaking at 423 nm (3.06 eV) and 505 nm (2.46 eV), respectively. The electron–hole recombination of localized excitons should responsible for the light emissions at 423 and 470 nm. Room temperature Raman spectrum of KTN nanoplates reveal that the frequencies of vibration mode are lower slightly than that of KTN bulk materials, and the scattering profile is to be more diffused and enlarged, which may be induced by the crystal structure defects, such as stacking faults.