Optical study of colloidal quantum dots : toward efficient emission and lasing upon single- and multi-photon excitation
Colloidal quantum dots (CQDs) have become the research hotspot due to their exceptional merits including the facile emission spectral tunability by size and composition tailoring, the solution processibility, the broad absorption and the narrow emission spectra and so on. In this thesis, main effort...
| Main Author: | |
|---|---|
| Other Authors: | |
| Format: | Thesis |
| Language: | English |
| Published: |
2015
|
| Subjects: | |
| Online Access: | https://hdl.handle.net/10356/65555 |
| _version_ | 1826127092293566464 |
|---|---|
| author | Wang, Yue |
| author2 | Sun Handong |
| author_facet | Sun Handong Wang, Yue |
| author_sort | Wang, Yue |
| collection | NTU |
| description | Colloidal quantum dots (CQDs) have become the research hotspot due to their exceptional merits including the facile emission spectral tunability by size and composition tailoring, the solution processibility, the broad absorption and the narrow emission spectra and so on. In this thesis, main efforts are devoted to explore the fundamental linear and nonlinear optical properties of CQDs and develop applications of CQD-based micro-lasers. The third-order nonlinear optical properties of heavy metal-free InP/ZnS CQDs have been comprehensively studied, which reveals that the InP/ZnS CQDs are potentially excellent fluorescent bio-probes under two-photon excitation. By rationally designing and employing the CdSe/CdS/ZnS core/shell/shell CQDs as the optical gain material, three-photon induced amplified spontaneous emission and lasing have been realized for the first time from CQDs. Record low threshold stimulated emission in blue spectral range have been achieved from the ternary alloy CdZnS/ZnS core/shell CQDs thanks to the intrinsic slow nonradiative Auger recombination. To solve the “green gap” challenge experienced in epitaxial semiconductor lasers, the optical gain properties of the green-emitting quaternary alloy CdZnSeS/ZnS core/shell has been comprehensively investigated for the first time, and ultra-low threshold stimulated emission in green region has been observed. Furthermore, low threshold whispering gallery mode lasers in blue and green regime under quasi-continuous wave pumping have been produced leveraging on CdZnS/ZnS and CdZnSeS/ZnS CQDs, respectively. Our results represent a great progress in the development of CQD-based lasers and hold strong potential in wide range of field in biology and photonics and their interaction of biophotonics. |
| first_indexed | 2024-10-01T07:03:05Z |
| format | Thesis |
| id | ntu-10356/65555 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T07:03:05Z |
| publishDate | 2015 |
| record_format | dspace |
| spelling | ntu-10356/655552023-02-28T23:52:35Z Optical study of colloidal quantum dots : toward efficient emission and lasing upon single- and multi-photon excitation Wang, Yue Sun Handong School of Physical and Mathematical Sciences DRNTU::Science::Physics::Optics and light Colloidal quantum dots (CQDs) have become the research hotspot due to their exceptional merits including the facile emission spectral tunability by size and composition tailoring, the solution processibility, the broad absorption and the narrow emission spectra and so on. In this thesis, main efforts are devoted to explore the fundamental linear and nonlinear optical properties of CQDs and develop applications of CQD-based micro-lasers. The third-order nonlinear optical properties of heavy metal-free InP/ZnS CQDs have been comprehensively studied, which reveals that the InP/ZnS CQDs are potentially excellent fluorescent bio-probes under two-photon excitation. By rationally designing and employing the CdSe/CdS/ZnS core/shell/shell CQDs as the optical gain material, three-photon induced amplified spontaneous emission and lasing have been realized for the first time from CQDs. Record low threshold stimulated emission in blue spectral range have been achieved from the ternary alloy CdZnS/ZnS core/shell CQDs thanks to the intrinsic slow nonradiative Auger recombination. To solve the “green gap” challenge experienced in epitaxial semiconductor lasers, the optical gain properties of the green-emitting quaternary alloy CdZnSeS/ZnS core/shell has been comprehensively investigated for the first time, and ultra-low threshold stimulated emission in green region has been observed. Furthermore, low threshold whispering gallery mode lasers in blue and green regime under quasi-continuous wave pumping have been produced leveraging on CdZnS/ZnS and CdZnSeS/ZnS CQDs, respectively. Our results represent a great progress in the development of CQD-based lasers and hold strong potential in wide range of field in biology and photonics and their interaction of biophotonics. DOCTOR OF PHILOSOPHY (SPMS) 2015-11-12T02:45:54Z 2015-11-12T02:45:54Z 2015 2015 Thesis Wang, Y. (2015). Optical study of colloidal quantum dots: toward efficient emission and lasing upon single- and multi-photon excitation. Doctoral thesis, Nanyang Technological University, Singapore. https://hdl.handle.net/10356/65555 10.32657/10356/65555 en 160 p. application/pdf |
| spellingShingle | DRNTU::Science::Physics::Optics and light Wang, Yue Optical study of colloidal quantum dots : toward efficient emission and lasing upon single- and multi-photon excitation |
| title | Optical study of colloidal quantum dots : toward efficient emission and lasing upon single- and multi-photon excitation |
| title_full | Optical study of colloidal quantum dots : toward efficient emission and lasing upon single- and multi-photon excitation |
| title_fullStr | Optical study of colloidal quantum dots : toward efficient emission and lasing upon single- and multi-photon excitation |
| title_full_unstemmed | Optical study of colloidal quantum dots : toward efficient emission and lasing upon single- and multi-photon excitation |
| title_short | Optical study of colloidal quantum dots : toward efficient emission and lasing upon single- and multi-photon excitation |
| title_sort | optical study of colloidal quantum dots toward efficient emission and lasing upon single and multi photon excitation |
| topic | DRNTU::Science::Physics::Optics and light |
| url | https://hdl.handle.net/10356/65555 |
| work_keys_str_mv | AT wangyue opticalstudyofcolloidalquantumdotstowardefficientemissionandlasinguponsingleandmultiphotonexcitation |