Quantum-Confined and Enhanced Optical Absorption of Colloidal PbS Quantum Dots at Wavelengths with Expected Bulk Behavior
Quantum-Confined and Enhanced Optical Absorption of Colloidal PbS Quantum Dots at Wavelengths with Expected Bulk Behavior
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DOI：
10.1021/acs.nanolett.6b05087
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发表时间：
2017-02-01
期刊：
影响因子：
10.8
通讯作者：
Giansante, Carlo
中科院分区：
文献类型：
--
作者：
Debellis, Doriana;Gigli, Giuseppe;Giansante, Carlo
如今，人们普遍认为胶体PbS量子点在400 nm以上的波长处具有块状光吸收特性。这个假设允许描述PbS QD光吸收，通过使用体光学常数和确定QD浓度胶体8解决方案从简单的分光光度测量。在这里，我们证明了PbS QD在整个近紫外-可见-近红外光谱范围内经历量子限制机制，因此在350和400 nm之间也已经被提出足以远高于带隙以抑制量子限制。这种效应对于小PbS QD（直径为100 nm）特别相关。
Nowadays it is well-accepted to attribute bulk-like optical absorption properties to colloidal PbS quantum dots (QDs) at wavelengths above 400 nm. This assumption permits to describe PbS QD light absorption by using bulk optical constants and to determine QD concentration in colloidal 8 solutions from simple spectrophotometric measurements. Here we demonstrate that PbS QDs experience the quantum confinement regime across the entire near UV-vis-NIR spectral range, therefore also between 350 and 400 nm already proposed to be sufficiently far above the band gap to suppress quantum confinement. This effect is particularly relevant for small PbS QDs (with diameter of