分类： 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间： 2017-05-02
He, J [He, Jun][ 1,2 ]
Xu, JT [Xu, Jingtao][ 2 ]
Liu, GQ [Liu, Guo-Qiang][ 2 ]
Shao, HZ [Shao, Hezhu][ 2 ]
Tan, XJ [Tan, Xiaojian][ 2 ]
Liu, Z [Liu, Zhu][ 2 ]
Xu, JQ [Xu, Jiaqiang][ 1 ]
Jiang, HC [Jiang, Haochuan][ 2 ]
Jiang, J [Jiang, Jun][ 2 ]
摘要： SnCdxTe materials were synthesized by the zone-melting method for this thermoelectric performance study. The X-ray diffraction results show that the lattice parameter decreases with increasing x, following Vegard's law of rock-salt structure SnTe and CdTe. Besides, the room temperature Seebeck coefficients of the SnCdxTe system are enhanced to >60 mV K 1, larger than those of Cd-doped SnTe synthesized by spark plasma sintering. A large power factor of $25 mW cm 1 K 1 is achieved in SnCd0.12Te at 820 K, which rivals those of high performance PbTe-based materials. As a result, the highest ZT of $1.03 at 820 K was achieved for SnCd0.12Te.
分类： 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间： 2017-05-02
Zhang, CH [Zhang, Changhua][ 1,2 ]
Liu, YF [Liu, Yongfu][ 2 ]
Zhang, JH [Zhang, Jiahua][ 3 ]
Zhang, X [Zhang, Xia][ 3 ]
Zhang, JX [Zhang, Jianxin][ 2,4 ]
Cheng, ZX [Cheng, Zhixuan][ 1 ]
Jiang, J [Jiang, Jun][ 2 ]
Jiang, HC [Jiang, Haochuan][ 2 ]
摘要： We obtained a single phase BLS:Eu2+, Ce3+, Mn2+ phosphor by solid-state reactions. Eu2+, Ce3+, and Mn2+ gives rise to the blue, green, and red emission, respectively. The Mn2+ red emission can be effectively enhanced via energy transfers from both Eu2+ and Ce3+. Thus a tunable full color emission from 410 to 750 nm was realized in this single phosphor. The Eu2+ ! Mn2+ energy transfer mechanism was investigated by the fluorescence decay curves. This single phosphor exhibits an efficient excitation band covering from 390 to 410 nm, which matches well with the emission light of the efficient NUV chips. The optimized BLS:Eu2+, Ce3+, Mn2+ phosphor shows a high quantum efficient of $62% and a good color stability. When this single phosphor was combined with a 395 nm NUV-chip, an ideal white LED with a high color render index (CRI) of 85 and a correlated color temperature (CCT) of 6300 K was obtained. This demonstrates the promising application of the BLS:Eu2+, Ce3+, Mn2+ single phosphor for the NUV-based white LEDs.
分类： 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间： 2017-05-02
Fu, YJ [Fu, Yajie][ 1,2 ]
Xu, JT [Xu, Jingtao][ 2 ]
Liu, GQ [Liu, Guo-Qiang][ 2 ]
Yang, JK [Yang, Jingkai]
Tan, XJ [Tan, Xiaojian][ 1,2 ]
Liu, Z [Liu, Zhu][ 2 ]
Qin, HM [Qin, Haiming][ 2 ]
Shao, HZ [Shao, Hezhu][ 2 ]
Jiang, HC [Jiang, Haochuan][ 2 ]
Liang, B [Liang, Bo][ 1 ]
Jiang, J [Jiang, Jun][ 2 ]
摘要： Tin selenide (SnSe) compound has attracted much attention due to its unprecedented high ZT (B2.6) in single crystals. The polycrystalline SnSe materials were then prepared to improve the mechanical performance for large-scaled application. However, the ZT values of 0.3–0.8 were much lower due to their poor electrical properties. In the present study, the zone melting method is employed to prepare the polycrystalline SnSe samples, which show highly textured structures and strong anisotropic thermoelectric performance. A maximum power factor (S2s) of 9.8 mW cm 1 K 2 was obtained in the polycrystalline samples, which is comparable with that of SnSe single crystals, resulting in a peak ZT of 0.92 at 873 K. The zone-melted ingot was then pulverized into powders and the bulk material was prepared by the spark plasma sintering (SPS) technique. As a result, the ZT value was enhanced to be over 1.0, owing to the slight reduction of lattice thermal conductivity and maintenance of electrical performance. The present investigation indicates that the TE performance of the SnSe compound can be significantly improved by the texture modulation.
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