Polarization Properties of Semiconductor Nanorod Heterostructures: From Single Particles to the Ensemble
Polarization Properties of Semiconductor Nanorod Heterostructures: From Single Particles to the Ensemble
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DOI：
10.1021/jz3021167
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发表时间：
2013-02-07
影响因子：
5.7
通讯作者：
Banin, Uri
中科院分区：
文献类型：
--
作者：
Hadar, Ido;Hitin, Gal B.;Banin, Uri
半导体异质结籽晶纳米棒表现出强烈的偏振发射，并且偏振程度由其形态和尺寸决定。结合光学和原子力显微镜被用来直接关联的发射偏振和单种子纳米棒的取向。对于CdSe/CdS球中棒（S@R）和棒中棒（R@R），发现发射沿着纳米棒的主轴偏振。对数百个单个纳米棒的统计分析显示，与S@R（p = 0.75）相比，R@R（p = 0.83）的偏振度p更高。这些结果是在很好的协议与合奏光选择各向异性测量在溶液中推断的值，建立其有效性的纳米棒样品。在此基础上，进行了光选择光致发光激发各向异性测量，提供了有关较高激子跃迁对称性的独特信息，并可以更好地区分纳米棒中介电和量子力学对极化的贡献。
Semiconductor heterostructured seeded nanorods exhibit intense polarized emission, and the degree of polarization is determined by their morphology and dimensions. Combined optical and atomic force microscopy were utilized to directly correlate the emission polarization and the orientation of single seeded nanorods. For both the CdSe/CdS sphere-in-rod (S@R) and rod-in-rod (R@R), the emission was found to be polarized along the nanorod's main axis. Statistical analysis for hundreds of single nanorods shows higher degree of polarization, p, for R@R (p = 0.83), in comparison to S@R (p = 0.75). These results are in good agreement with the values inferred by ensemble photoselection anisotropy measurements in solution, establishing its validity for nanorod samples. On this basis, photoselection photoluminescence excitation anisotropy measurements were carried out providing unique information concerning the symmetry of higher excitonic transitions and allowing for a better distinction between the dielectric and the quantum-mechanical contributions to polarization in nanorods.