CdSe/ZnS quantum dot size dependent carrier relaxation in hybrid organic/inorganic system
We have studied the CdSe/ZnS quantum dot (QD) size dependent carrier relaxation dynamics in hybrid organic/inorganic system for the first time. The QD size was from 5.0 to 2.0 nm. The optical narrow emission of quantum dots shift to higher energies as the size of dots gets smaller due to the 3-D con...
| Main Authors: | , , |
|---|---|
| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
| Published: |
2013
|
| Online Access: | https://hdl.handle.net/10356/85271 http://hdl.handle.net/10220/13657 |
| _version_ | 1826111350664855552 |
|---|---|
| author | Uddin, A. Wong, H. S. Teo, C. C. |
| author2 | School of Materials Science & Engineering |
| author_facet | School of Materials Science & Engineering Uddin, A. Wong, H. S. Teo, C. C. |
| author_sort | Uddin, A. |
| collection | NTU |
| description | We have studied the CdSe/ZnS quantum dot (QD) size dependent carrier relaxation dynamics in hybrid organic/inorganic system for the first time. The QD size was from 5.0 to 2.0 nm. The optical narrow emission of quantum dots shift to higher energies as the size of dots gets smaller due to the 3-D confinement which splits the continuous band into a series of discrete quantum states and increases the band gap. The carrier relaxation time in QDs was found to increases as the pump power increased and reached saturation at ∼326 μW excitation, probably due to the saturation of traps with the photoexcited charge carriers within individual nanoparticles. The relaxation rate was also increased with pump power, indicating that new relaxation processes e.g., Auger processes and faster carrier trapping were present. The slow decay component remained at the lowest power (51 μW) excitation with no fast decay present. The decrease of CdSe/ZnS QD size increased the fast component relaxation rate probably due to a higher number of surface defects hence inducing faster trapping of carriers by shallow trap state. |
| first_indexed | 2024-10-01T02:49:15Z |
| format | Journal Article |
| id | ntu-10356/85271 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T02:49:15Z |
| publishDate | 2013 |
| record_format | dspace |
| spelling | ntu-10356/852712020-06-01T10:01:39Z CdSe/ZnS quantum dot size dependent carrier relaxation in hybrid organic/inorganic system Uddin, A. Wong, H. S. Teo, C. C. School of Materials Science & Engineering We have studied the CdSe/ZnS quantum dot (QD) size dependent carrier relaxation dynamics in hybrid organic/inorganic system for the first time. The QD size was from 5.0 to 2.0 nm. The optical narrow emission of quantum dots shift to higher energies as the size of dots gets smaller due to the 3-D confinement which splits the continuous band into a series of discrete quantum states and increases the band gap. The carrier relaxation time in QDs was found to increases as the pump power increased and reached saturation at ∼326 μW excitation, probably due to the saturation of traps with the photoexcited charge carriers within individual nanoparticles. The relaxation rate was also increased with pump power, indicating that new relaxation processes e.g., Auger processes and faster carrier trapping were present. The slow decay component remained at the lowest power (51 μW) excitation with no fast decay present. The decrease of CdSe/ZnS QD size increased the fast component relaxation rate probably due to a higher number of surface defects hence inducing faster trapping of carriers by shallow trap state. 2013-09-24T07:26:32Z 2019-12-06T16:00:42Z 2013-09-24T07:26:32Z 2019-12-06T16:00:42Z 2012 2012 Journal Article Uddin, A., Wong, H. S., & Teo, C. C. (2012). CdSe/ZnS Quantum Dot Size Dependent Carrier Relaxation in Hybrid Organic/Inorganic System. Journal of Nanoscience and Nanotechnology, 12(10), 7853-7859(7). https://hdl.handle.net/10356/85271 http://hdl.handle.net/10220/13657 10.1166/jnn.2012.6615 en Journal of nanoscience and nanotechnology |
| spellingShingle | Uddin, A. Wong, H. S. Teo, C. C. CdSe/ZnS quantum dot size dependent carrier relaxation in hybrid organic/inorganic system |
| title | CdSe/ZnS quantum dot size dependent carrier relaxation in hybrid organic/inorganic system |
| title_full | CdSe/ZnS quantum dot size dependent carrier relaxation in hybrid organic/inorganic system |
| title_fullStr | CdSe/ZnS quantum dot size dependent carrier relaxation in hybrid organic/inorganic system |
| title_full_unstemmed | CdSe/ZnS quantum dot size dependent carrier relaxation in hybrid organic/inorganic system |
| title_short | CdSe/ZnS quantum dot size dependent carrier relaxation in hybrid organic/inorganic system |
| title_sort | cdse zns quantum dot size dependent carrier relaxation in hybrid organic inorganic system |
| url | https://hdl.handle.net/10356/85271 http://hdl.handle.net/10220/13657 |
| work_keys_str_mv | AT uddina cdseznsquantumdotsizedependentcarrierrelaxationinhybridorganicinorganicsystem AT wonghs cdseznsquantumdotsizedependentcarrierrelaxationinhybridorganicinorganicsystem AT teocc cdseznsquantumdotsizedependentcarrierrelaxationinhybridorganicinorganicsystem |