Seeing Multiexcitons through Sample Inhomogeneity: Band-Edge Biexciton Structure in CdSe Nanocrystals Revealed by Two-Dimensional Electronic Spectroscopy,Nano Letters

当前位置： X-MOL 学术 › Nano Lett. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Seeing Multiexcitons through Sample Inhomogeneity: Band-Edge Biexciton Structure in CdSe Nanocrystals Revealed by Two-Dimensional Electronic Spectroscopy
Nano Letters ( IF 9.6 ) Pub Date : 2018-03-28 00:00:00 , DOI: 10.1021/acs.nanolett.8b00470
Hélène Seiler ₁ , Samuel Palato ₁ , Colin Sonnichsen ₁ , Harry Baker ₁ , Patanjali Kambhampati ₁

Affiliation

The electronic structure of multiexcitons significantly impacts the performance of nanostructures in lasing and light-emitting applications. However, these multiexcitons remain poorly understood due to their complexity arising from many-body physics. Standard transient-absorption and photoluminescence spectroscopies are unable to unambiguously distinguish effects of sample inhomogeneity from exciton–biexciton interactions. Here, we exploit the energy and time resolution of two-dimensional electronic spectroscopy to access the electronic structure of the band-edge biexciton in colloidal CdSe quantum dots. By removing effects of inhomogeneities, we show that the band-edge biexciton structure must consist of a discrete manifold of electronic states. Furthermore, the biexciton states within the manifold feature distinctive binding energies. Our findings have direct implications for optical gain thresholds and efficiency droop in light-emitting devices and provide experimental measures of many-body physics in nanostructures.

中文翻译：

通过样品的不均匀性看到多激子：二维电子光谱揭示的CdSe纳米晶体中的带边双激子结构。

多激子的电子结构显着影响激光和发光应用中纳米结构的性能。但是，由于多体激子由于多体物理学而引起的复杂性，因此人们对其了解仍然很少。标准的瞬态吸收和光致发光光谱学无法将样品不均匀性的影响与激子-比西旋相互作用相互作用区分开来。在这里，我们利用二维电子光谱的能量和时间分辨率来访问胶体CdSe量子点中带边双激子的电子结构。通过消除不均匀性的影响，我们表明带边缘双激子结构必须由电子状态的离散流形组成。此外，流形内的双激态具有独特的结合能。

更新日期：2018-03-28

点击分享查看原文

点击收藏

阅读更多本刊最新论文本刊介绍/投稿指南11