Luminescence mechanism and energy level structure of Eu-doped GaN powders investigated by cathodoluminescence spectroscopy
Luminescence mechanism and energy level structure of Eu-doped GaN powders investigated by cathodoluminescence spectroscopy
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DOI：
10.1007/s11433-013-5385-x
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发表时间：
2014-02
期刊：
影响因子：
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通讯作者：
Xiaodan Wang;Xionghui Zeng;Ke Xu;Hongmin Mao;Chunlan Ma
中科院分区：
文献类型：
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作者：
Xiaodan Wang;Xionghui Zeng;Ke Xu;Hongmin Mao;Chunlan Ma
采用共沉淀法制备了1.5at%Eu掺杂的GaN粉体。粉末X射线衍射（XRD）结果表明，只有纤锌矿相。分别在室温和液氮温度下测量了阴极射线发光光谱。从室温到液氮温度，GaN的带间发光从373 nm移动到368 nm。在537、557、579、590、597、614、653和701 nm处的发光峰归属于GaN基质中Eu离子的跃迁，峰位不受温度变化的影响。随着加速电压的增加，各发光峰的强度均增加。最强的发光峰在614 nm处呈现出非对称的形状，通过洛伦兹拟合发现，发光峰由612、615和621 nm组成，说明Eu掺杂GaN粉末中存在Eu3+离子的氧和氮环境。
1.5at% Eu-doped GaN powders were prepared by a co-precipitation method. Powder X-ray diffraction (XRD) results shows that there is only the wurtzite phase. Cathodoluminescence spectra were measured at room temperature and liquid nitrogen temperature, respectively. The band-to-band luminescence of GaN was shifted from 373 nm to 368 nm with the temperature decreasing from room temperature to liquid nitrogen temperature. The luminescence peaks at 537, 557, 579, 590, 597, 614, 653 and 701 nm are attributed to the Eu ions related transitions in the host of GaN powders and the peak positions were not influenced by the variation of temperature. With the increase of accelerating voltage, the intensity of all luminescence peaks was increased. The strongest luminescence peak at 614 nm shows non-symmetrical shape and is composed of 612, 615 and 621 nm through Lorentzian fitting, which indicates there are oxygen and nitrogen environments of the Eu3+ions in the Eu-doped GaN powders.