Optical Gain of Vertically Coupled Cd<sub>0.6</sub>Zn<sub>0.4</sub>Te/ZnTe Quantum Dots
The optical modal gain of Cd<sub>0.6</sub>Zn<sub>0.4</sub>Te/ZnTe double quantum dots was measured using a variable stripe length method, where large and small quantum dots are separated with a ZnTe layer. With a large (~18 nm) separation layer thickness of ZnTe, two gain spe...
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MDPI AG
2023-02-01
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| Series: | Nanomaterials |
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| author | Ming Mei Minju Kim Minwoo Kim Inhong Kim Hong Seok Lee Robert A. Taylor Kwangseuk Kyhm |
| author_facet | Ming Mei Minju Kim Minwoo Kim Inhong Kim Hong Seok Lee Robert A. Taylor Kwangseuk Kyhm |
| author_sort | Ming Mei |
| collection | DOAJ |
| description | The optical modal gain of Cd<sub>0.6</sub>Zn<sub>0.4</sub>Te/ZnTe double quantum dots was measured using a variable stripe length method, where large and small quantum dots are separated with a ZnTe layer. With a large (~18 nm) separation layer thickness of ZnTe, two gain spectra were observed, which correspond to the confined exciton levels of the large and small quantum dots, respectively. With a small (~6 nm) separation layer thickness of ZnTe, a merged single gain spectrum was observed. This can be attributed to a coupled state between large and small quantum dots. Because the density of large quantum dots (4 × 10<sup>10</sup> cm<sup>−2</sup>) is twice the density of small quantum dots (2 × 10<sup>10</sup> cm<sup>−2</sup>), the density of the coupled quantum dots is determined by that of small quantum dots. As a result, we found that the peak gain (123.9 ± 9.2 cm<sup>−1</sup>) with the 6 nm separation layer is comparable to that (125.2 ± 29.2 cm<sup>−1</sup>) of the small quantum dots with the 18 nm separation layer. |
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| language | English |
| last_indexed | 2024-03-11T08:19:30Z |
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| spelling | doaj.art-01f7e074962a4bc586bf91605e5c54e52023-11-16T22:27:57ZengMDPI AGNanomaterials2079-49912023-02-0113471610.3390/nano13040716Optical Gain of Vertically Coupled Cd<sub>0.6</sub>Zn<sub>0.4</sub>Te/ZnTe Quantum DotsMing Mei0Minju Kim1Minwoo Kim2Inhong Kim3Hong Seok Lee4Robert A. Taylor5Kwangseuk Kyhm6Department of Optics & Cogno-Mechatronics Engineering, Pusan National University, Busan 46241, Republic of KoreaSmart Gym-Based Translational Research Center for Active Senior’s Healthcare, Pukyong National University, Busan 48513, Republic of KoreaDepartment of Optics & Cogno-Mechatronics Engineering, Pusan National University, Busan 46241, Republic of KoreaDepartment of Optics & Cogno-Mechatronics Engineering, Pusan National University, Busan 46241, Republic of KoreaDepartment of Physics, Jeonbuk National University, Jeonju 54896, Republic of KoreaDepartment of Physics, University of Oxford, Oxford OX1 3PU, UKDepartment of Optics & Cogno-Mechatronics Engineering, Pusan National University, Busan 46241, Republic of KoreaThe optical modal gain of Cd<sub>0.6</sub>Zn<sub>0.4</sub>Te/ZnTe double quantum dots was measured using a variable stripe length method, where large and small quantum dots are separated with a ZnTe layer. With a large (~18 nm) separation layer thickness of ZnTe, two gain spectra were observed, which correspond to the confined exciton levels of the large and small quantum dots, respectively. With a small (~6 nm) separation layer thickness of ZnTe, a merged single gain spectrum was observed. This can be attributed to a coupled state between large and small quantum dots. Because the density of large quantum dots (4 × 10<sup>10</sup> cm<sup>−2</sup>) is twice the density of small quantum dots (2 × 10<sup>10</sup> cm<sup>−2</sup>), the density of the coupled quantum dots is determined by that of small quantum dots. As a result, we found that the peak gain (123.9 ± 9.2 cm<sup>−1</sup>) with the 6 nm separation layer is comparable to that (125.2 ± 29.2 cm<sup>−1</sup>) of the small quantum dots with the 18 nm separation layer.https://www.mdpi.com/2079-4991/13/4/716optical modal gainamplified spontaneous emissionCdZnTeexcitonquantum dots |
| spellingShingle | Ming Mei Minju Kim Minwoo Kim Inhong Kim Hong Seok Lee Robert A. Taylor Kwangseuk Kyhm Optical Gain of Vertically Coupled Cd<sub>0.6</sub>Zn<sub>0.4</sub>Te/ZnTe Quantum Dots Nanomaterials optical modal gain amplified spontaneous emission CdZnTe exciton quantum dots |
| title | Optical Gain of Vertically Coupled Cd<sub>0.6</sub>Zn<sub>0.4</sub>Te/ZnTe Quantum Dots |
| title_full | Optical Gain of Vertically Coupled Cd<sub>0.6</sub>Zn<sub>0.4</sub>Te/ZnTe Quantum Dots |
| title_fullStr | Optical Gain of Vertically Coupled Cd<sub>0.6</sub>Zn<sub>0.4</sub>Te/ZnTe Quantum Dots |
| title_full_unstemmed | Optical Gain of Vertically Coupled Cd<sub>0.6</sub>Zn<sub>0.4</sub>Te/ZnTe Quantum Dots |
| title_short | Optical Gain of Vertically Coupled Cd<sub>0.6</sub>Zn<sub>0.4</sub>Te/ZnTe Quantum Dots |
| title_sort | optical gain of vertically coupled cd sub 0 6 sub zn sub 0 4 sub te znte quantum dots |
| topic | optical modal gain amplified spontaneous emission CdZnTe exciton quantum dots |
| url | https://www.mdpi.com/2079-4991/13/4/716 |
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