氨化法制备GaN：Tb纳米颗粒的光学性能

摘要

利用简单的氨还原方法制备了GaN：Tb纳米颗粒. X射线衍射结果显示纳米颗粒为六方结构,根据Scherrer公式,计算得到了GaN：Tb纳米颗粒的平均晶粒大小为21.2 nm；透射电子显微镜结果显示为GaN：Tb纳米颗粒尺寸均匀,尺寸大小约为20 nm；除正常的GaN Raman振动模式外,还观察到了251和414 cm−12个额外的Raman散射峰,前者是表面无序或尺寸限制效应造成的,而后者则是八面体Ga-N6振动模式；最后,测量了GaN：Tb纳米颗粒的室温光致发光谱,获得了Tb3+离子在可见光区(位于493.9,551.2,594.4和630.1 nm)的本征发光.%GaN:Tb nanoparticles are synthesized by simple ammonification of a mixture of Ga(NO3)3 and Tb(NO3)3. The XRD result shows that the sample predominantly presents hexagonal phase of GaN and its average grain size is 22.1 nm. TEM images show that the sizes of the particles are almost uniform. Besides conventional GaN Raman shifts, two extra peaks at 251 and 414 cm−1 observed in the Raman spectra can be attributed to the phonons activated by surface disorders or finite-size effects and vibration mode of N-rich octahedral Ga-N6 bonds, respectively. From photoluminescence spectra, four characteristic peaks of Tb3+ions are clearly observed:5D4→7 F6 (493.9 nm), 5D4→7 F5 (551.2 nm), 5D4→7 F4 (594.4 nm), 5D4→7 F3 (630.1 nm).