Reversible Tunability of the Near-Infrared Valence Band Plasmon Resonance in Cu2-xSe Nanocrystals
Reversible Tunability of the Near-Infrared Valence Band Plasmon Resonance in Cu2-xSe Nanocrystals
复制标题
DOI：
10.1021/ja2016284
复制
发表时间：
2011-07-27
影响因子：
15
通讯作者：
Manna, Liberato
中科院分区：
文献类型：
--
作者：
Dorfs, Dirk;Haertling, Thomas;Manna, Liberato
我们证明了胶体Cu 2-xSe纳米晶体由于正电荷载流子振荡的激发而表现出明确的红外吸收带（即，价带等离子体激元模式），其可以通过改变铜化学计量在宽度和位置上可逆地调谐。通过氧化Cu 2Se纳米晶体（在暴露于氧气或Ce（IV）络合物时），x的值可以从0（无等离子体吸收，然后在1700 nm处的宽峰）递增地变化到0.4（在1100 nm处的窄等离子体带），并且可以通过添加Cu（I）络合物将其递增地恢复到零。实验观察到的等离子体激元行为与基于静电近似的计算结果吻合良好。
We demonstrate that colloidal Cu2-xSe nanocrystals exhibit a well-defined infrared absorption band due to the excitation of positive charge carrier oscillations (i.e., a valence band plasmon mode), which can be tuned reversibly in width and position by varying the copper stoichiometry. The value of x could be incrementally varied from 0 (no plasmon absorption, then a broad peak at 1700 nm) to 0.4 (narrow plasmon band at 1100 nm) by oxidizing Cu2Se nanocrystals (upon exposure either to oxygen or to a Ce(IV) complex), and it could be incrementally restored back to zero by the addition of a Cu(I) complex. The experimentally observed plasmonic behavior is in good agreement with calculations based on the electrostatic approximation.