Understanding the features in the ultrafast transient absorption spectra of CdSe quantum dots
We describe a model to explain the features of the ultrafast transient absorption (TA) spectra of CdSe core type quantum dots (QDs). The measured TA spectrum consists of contributions by the ground state bleach (GSB), stimulated emission (SE) and excited state absorption (ESA) processes associated w...
| Main Authors: | , , , , |
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| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
| Published: |
2017
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| Online Access: | https://hdl.handle.net/10356/85126 http://hdl.handle.net/10220/43633 |
| _version_ | 1811692200419917824 |
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| author | Zhang, Cheng Do, Thanh Nhut Ong, Xuanwei Chan, Yinthai Tan, Howe-Siang |
| author2 | School of Physical and Mathematical Sciences |
| author_facet | School of Physical and Mathematical Sciences Zhang, Cheng Do, Thanh Nhut Ong, Xuanwei Chan, Yinthai Tan, Howe-Siang |
| author_sort | Zhang, Cheng |
| collection | NTU |
| description | We describe a model to explain the features of the ultrafast transient absorption (TA) spectra of CdSe core type quantum dots (QDs). The measured TA spectrum consists of contributions by the ground state bleach (GSB), stimulated emission (SE) and excited state absorption (ESA) processes associated with the three lowest energy transition of the QDs. We model the shapes of the GSB, SE and ESA spectral components after fits to the linear absorption. The spectral positions of the ESA components take into account the biexcitonic binding energy. In order to obtain the correct weightage of the GSB, SE and ESA components to the TA spectrum, we enumerate the set of coherence transfer pathways associated with these processes. From our fits of the experimental TA spectra of 65 Å diameter QDs, biexcitonic binding energies for the three lowest energy transitions are obtained. |
| first_indexed | 2024-10-01T06:32:00Z |
| format | Journal Article |
| id | ntu-10356/85126 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T06:32:00Z |
| publishDate | 2017 |
| record_format | dspace |
| spelling | ntu-10356/851262023-02-28T19:31:28Z Understanding the features in the ultrafast transient absorption spectra of CdSe quantum dots Zhang, Cheng Do, Thanh Nhut Ong, Xuanwei Chan, Yinthai Tan, Howe-Siang School of Physical and Mathematical Sciences CdSe quantum dots Nonlinear optical spectroscopy We describe a model to explain the features of the ultrafast transient absorption (TA) spectra of CdSe core type quantum dots (QDs). The measured TA spectrum consists of contributions by the ground state bleach (GSB), stimulated emission (SE) and excited state absorption (ESA) processes associated with the three lowest energy transition of the QDs. We model the shapes of the GSB, SE and ESA spectral components after fits to the linear absorption. The spectral positions of the ESA components take into account the biexcitonic binding energy. In order to obtain the correct weightage of the GSB, SE and ESA components to the TA spectrum, we enumerate the set of coherence transfer pathways associated with these processes. From our fits of the experimental TA spectra of 65 Å diameter QDs, biexcitonic binding energies for the three lowest energy transitions are obtained. MOE (Min. of Education, S’pore) Accepted version 2017-08-25T06:21:47Z 2019-12-06T15:57:37Z 2017-08-25T06:21:47Z 2019-12-06T15:57:37Z 2016 Journal Article Zhang, C., Do, T. N., Ong, X., Chan, Y., & Tan, H.-S. (2016). Understanding the features in the ultrafast transient absorption spectra of CdSe quantum dots. Chemical Physics, 481, 157-164. 0301-0104 https://hdl.handle.net/10356/85126 http://hdl.handle.net/10220/43633 10.1016/j.chemphys.2016.08.027 en Chemical Physics © 2016 Elsevier. This is the author created version of a work that has been peer reviewed and accepted for publication by Chemical Physics, Elsevier. It incorporates referee’s comments but changes resulting from the publishing process, such as copyediting, structural formatting, may not be reflected in this document. The published version is available at: [http://dx.doi.org/10.1016/j.chemphys.2016.08.027]. 31 p. application/pdf |
| spellingShingle | CdSe quantum dots Nonlinear optical spectroscopy Zhang, Cheng Do, Thanh Nhut Ong, Xuanwei Chan, Yinthai Tan, Howe-Siang Understanding the features in the ultrafast transient absorption spectra of CdSe quantum dots |
| title | Understanding the features in the ultrafast transient absorption spectra of CdSe quantum dots |
| title_full | Understanding the features in the ultrafast transient absorption spectra of CdSe quantum dots |
| title_fullStr | Understanding the features in the ultrafast transient absorption spectra of CdSe quantum dots |
| title_full_unstemmed | Understanding the features in the ultrafast transient absorption spectra of CdSe quantum dots |
| title_short | Understanding the features in the ultrafast transient absorption spectra of CdSe quantum dots |
| title_sort | understanding the features in the ultrafast transient absorption spectra of cdse quantum dots |
| topic | CdSe quantum dots Nonlinear optical spectroscopy |
| url | https://hdl.handle.net/10356/85126 http://hdl.handle.net/10220/43633 |
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