InP@ZnSeS, Core@Composition Gradient Shell Quantum Dots with Enhanced Stability
InP@ZnSeS, Core@Composition Gradient Shell Quantum Dots with Enhanced Stability
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DOI：
10.1021/cm201550w
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发表时间：
2011-10-25
影响因子：
8.6
通讯作者：
Lee, Seonghoon
中科院分区：
文献类型：
--
作者：
Lim, Jaehoon;Bae, Wan Ki;Lee, Seonghoon
利用TOPSe和TOPS之间的反应性差异，我们在径向上合成了具有组成梯度的InP@ZnSeS量子点，其中ZnSe减轻了晶格应变，ZnS保护了量子点不被降解，从而获得了高QE和光化学稳定性的量子点。在系统研究壳层纳米结构与量子点稳定性之间的关系方面，我们证明了具有厚梯度壳层的量子点具有高QE，并且在紫外线照射，配体交换或严格纯化下对壳层降解的稳定性大大增强。这种增强的稳定性InP@ZnSeS量子点是由于组成梯度壳的均匀性提高，激子波函数的有效限制，以及通过光氧化或配体交换产生的表面态最小化的表面氧化和非辐射衰变。使用稳定性增强的InP@ZnSeS量子点，我们能够展示基于inp的胶体绿色发光量子点led。虽然目前InP@ZnSeS量子点的现状还没有完全优化到实现实际光电器件，但本研究采用的方法（即由前驱体的反应性差异自然形成的成分梯度壳结构）将为合成具有先进纳米结构的InP量子点提供线索。
Utilizing the reactivity difference between TOPSe and TOPS, we synthesized InP@ZnSeS QDs with the composition gradient in a radial direction where ZnSe alleviated lattice strain and ZnS protected QDs from degradation so that we achieved QDs with high QE and photo/chemical stability. In terms of systematic investigation on the relationship between the shell nanostructure and QD stability, we demonstrated that QDs with thick gradient shells exhibited high QE and much enhanced stability against the shell degradation under UV irradiation, ligand exchange, or rigorous purification. This enhanced stability of InP@ZnSeS QDs is attributed to the improved uniformity of composition gradient shells, the efficient confinement of exciton wavefunctions, and the minimized surface oxidation and non-radiative decay via surface states generated by photo-oxidation or ligand exchange. Using InP@ZnSeS QDs with enhanced stability, we were able to demonstrate InP-based colloidal green-emitting QD-LEDs. Although the current status of InP@ZnSeS QDs is not fully optimized to realize practical optoelectronic devices, the approach taken in the present study (i.e., the composition gradient shell structure naturally made from reactivity difference in precursors) will give clues to facilitate the synthesis of InP QDs with advanced nanostructures.