Intrinsic Optical and Electronic Properties from Quantitative Analysis of Plasmonic Semiconductor Nanocrystal Ensemble Optical Extinction
Intrinsic Optical and Electronic Properties from Quantitative Analysis of Plasmonic Semiconductor Nanocrystal Ensemble Optical Extinction
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DOI：
10.1021/acs.jpcc.0c08195
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发表时间：
2020-11-05
影响因子：
3.7
通讯作者：
Milliron, Delia J.
中科院分区：
文献类型：
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作者：
Gibbs, Stephen L.;Staller, Corey M.;Milliron, Delia J.
由掺杂半导体纳米晶体（NC）中的局部表面等离子体共振引起的光学消光光谱具有由自由载流子浓度和用于阻尼这些自由载流子的振荡的各种机制确定的强度和线形。然而，当测量系综的光谱时，这些固有性质被非均匀加宽所卷积。我们发现，传统的德鲁德近似不配备从掺杂半导体NC的异质系综拟合光谱，并产生违反米氏散射理论的拟合结果。非均匀系综德鲁德近似（HEDA）模型纠正了这个问题，占系综非均匀性和近地表耗尽。HEDA模型适用于锡掺杂的氧化铟NC的范围内的大小和掺杂水平，但我们希望它被用于任何各向同性等离子体粒子在准静态政权。它捕获单个NC光学特性及其对系综光谱的贡献，从而能够从系综测量分析固有NC特性。在每个合奏的平均NC的质量因素进行量化，并发现显着高于合奏。载流子迁移率和电导率来自HEDA拟合匹配报告中的散装薄膜文献。
The optical extinction spectra arising from localized surface plasmon resonance in doped semiconductor nanocrystals (NCs) have intensities and lineshapes determined by free charge carrier concentrations and various mechanisms for damping the oscillation of those free carriers. However, these intrinsic properties are convoluted by heterogeneous broadening when measuring the spectra of ensembles. We reveal that the traditional Drude approximation is not equipped to fit spectra from a heterogeneous ensemble of doped semiconductor NCs and produces fit results that violate Mie scattering theory. The heterogeneous ensemble Drude approximation (HEDA) model rectifies this issue by accounting for ensemble heterogeneity and near-surface depletion. The HEDA model is applied to tin-doped indium oxide NCs for a range of sizes and doping levels, but we expect it to be employed for any isotropic plasmonic particles in the quasistatic regime. It captures individual NC optical properties and their contributions to the ensemble spectra, thereby enabling the analysis of intrinsic NC properties from an ensemble measurement. Quality factors for the average NC in each ensemble are quantified and found to be notably higher than those of the ensemble. Carrier mobility and conductivity derived from the HEDA fits matches that reported in the bulk thin-film literature.