Host exciton confinement for enhanced Förster‐transfer‐blend gain media yielding highly efficient yellow‐green lasers
This paper reports state‐of‐the‐art fluorene‐based yellow‐green conjugated polymer blend gain media using Förster resonant‐energy‐transfer from novel blue‐emitting hosts to yield low threshold (≤7 kW cm−2) lasers operating between 540 and 590 nm. For poly(9,9‐dioctylfluorene‐co‐benzothiadiazole) (F8...
| Main Authors: | , , , , , , , , , , , , |
|---|---|
| Format: | Journal article |
| Published: |
Wiley‐VCH Verlag
2018
|
| _version_ | 1797088920486281216 |
|---|---|
| author | Zhang, Q Liu, J Wei, Q Guo, X Xu, Y Xia, R Xie, L Qian, Y Sun, C Lüer, L Cabanillas-Gonzalez, J Bradley, D Huang, W |
| author_facet | Zhang, Q Liu, J Wei, Q Guo, X Xu, Y Xia, R Xie, L Qian, Y Sun, C Lüer, L Cabanillas-Gonzalez, J Bradley, D Huang, W |
| author_sort | Zhang, Q |
| collection | OXFORD |
| description | This paper reports state‐of‐the‐art fluorene‐based yellow‐green conjugated polymer blend gain media using Förster resonant‐energy‐transfer from novel blue‐emitting hosts to yield low threshold (≤7 kW cm−2) lasers operating between 540 and 590 nm. For poly(9,9‐dioctylfluorene‐co‐benzothiadiazole) (F8BT) (15 wt%) blended with the newly synthesized 3,6‐bis(2,7‐di([1,1′‐biphenyl]‐4‐yl)‐9‐phenyl‐9H‐fluoren‐9‐yl)‐9‐octyl‐9H–carbazole (DBPhFCz) a highly desirable more than four times increase (relative to F8BT) in net optical gain to 90 cm−1 and 34 times reduction in amplified spontaneous emission threshold to 3 µJ cm−2 is achieved. Detailed transient absorption studies confirm effective exciton confinement with consequent diffusion‐limited polaron‐pair generation for DBPhFCz. This delays formation of host photoinduced absorption long enough to enable build‐up of the spectrally overlapped, guest optical gain, and resolves a longstanding issue for conjugated polymer photonics. The comprehensive study further establishes that limiting host conjugation length is a key factor therein, with 9,9‐dialkylfluorene trimers also suitable hosts for F8BT but not pentamers, heptamers, or polymers. It is additionally demonstrated that the host highest occupied and lowest unoccupied molecular orbitals can be tuned independently from the guest gain properties. This provides the tantalizing prospect of enhanced electron and hole injection and transport without endangering efficient optical gain; a scenario of great interest for electrically pumped amplifiers and lasers. |
| first_indexed | 2024-03-07T02:57:01Z |
| format | Journal article |
| id | oxford-uuid:afa938dd-c73b-4811-af71-ba44184179b9 |
| institution | University of Oxford |
| last_indexed | 2024-03-07T02:57:01Z |
| publishDate | 2018 |
| publisher | Wiley‐VCH Verlag |
| record_format | dspace |
| spelling | oxford-uuid:afa938dd-c73b-4811-af71-ba44184179b92022-03-27T03:51:05ZHost exciton confinement for enhanced Förster‐transfer‐blend gain media yielding highly efficient yellow‐green lasersJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:afa938dd-c73b-4811-af71-ba44184179b9Symplectic Elements at OxfordWiley‐VCH Verlag2018Zhang, QLiu, JWei, QGuo, XXu, YXia, RXie, LQian, YSun, CLüer, LCabanillas-Gonzalez, JBradley, DHuang, WThis paper reports state‐of‐the‐art fluorene‐based yellow‐green conjugated polymer blend gain media using Förster resonant‐energy‐transfer from novel blue‐emitting hosts to yield low threshold (≤7 kW cm−2) lasers operating between 540 and 590 nm. For poly(9,9‐dioctylfluorene‐co‐benzothiadiazole) (F8BT) (15 wt%) blended with the newly synthesized 3,6‐bis(2,7‐di([1,1′‐biphenyl]‐4‐yl)‐9‐phenyl‐9H‐fluoren‐9‐yl)‐9‐octyl‐9H–carbazole (DBPhFCz) a highly desirable more than four times increase (relative to F8BT) in net optical gain to 90 cm−1 and 34 times reduction in amplified spontaneous emission threshold to 3 µJ cm−2 is achieved. Detailed transient absorption studies confirm effective exciton confinement with consequent diffusion‐limited polaron‐pair generation for DBPhFCz. This delays formation of host photoinduced absorption long enough to enable build‐up of the spectrally overlapped, guest optical gain, and resolves a longstanding issue for conjugated polymer photonics. The comprehensive study further establishes that limiting host conjugation length is a key factor therein, with 9,9‐dialkylfluorene trimers also suitable hosts for F8BT but not pentamers, heptamers, or polymers. It is additionally demonstrated that the host highest occupied and lowest unoccupied molecular orbitals can be tuned independently from the guest gain properties. This provides the tantalizing prospect of enhanced electron and hole injection and transport without endangering efficient optical gain; a scenario of great interest for electrically pumped amplifiers and lasers. |
| spellingShingle | Zhang, Q Liu, J Wei, Q Guo, X Xu, Y Xia, R Xie, L Qian, Y Sun, C Lüer, L Cabanillas-Gonzalez, J Bradley, D Huang, W Host exciton confinement for enhanced Förster‐transfer‐blend gain media yielding highly efficient yellow‐green lasers |
| title | Host exciton confinement for enhanced Förster‐transfer‐blend gain media yielding highly efficient yellow‐green lasers |
| title_full | Host exciton confinement for enhanced Förster‐transfer‐blend gain media yielding highly efficient yellow‐green lasers |
| title_fullStr | Host exciton confinement for enhanced Förster‐transfer‐blend gain media yielding highly efficient yellow‐green lasers |
| title_full_unstemmed | Host exciton confinement for enhanced Förster‐transfer‐blend gain media yielding highly efficient yellow‐green lasers |
| title_short | Host exciton confinement for enhanced Förster‐transfer‐blend gain media yielding highly efficient yellow‐green lasers |
| title_sort | host exciton confinement for enhanced forster transfer blend gain media yielding highly efficient yellow green lasers |
| work_keys_str_mv | AT zhangq hostexcitonconfinementforenhancedforstertransferblendgainmediayieldinghighlyefficientyellowgreenlasers AT liuj hostexcitonconfinementforenhancedforstertransferblendgainmediayieldinghighlyefficientyellowgreenlasers AT weiq hostexcitonconfinementforenhancedforstertransferblendgainmediayieldinghighlyefficientyellowgreenlasers AT guox hostexcitonconfinementforenhancedforstertransferblendgainmediayieldinghighlyefficientyellowgreenlasers AT xuy hostexcitonconfinementforenhancedforstertransferblendgainmediayieldinghighlyefficientyellowgreenlasers AT xiar hostexcitonconfinementforenhancedforstertransferblendgainmediayieldinghighlyefficientyellowgreenlasers AT xiel hostexcitonconfinementforenhancedforstertransferblendgainmediayieldinghighlyefficientyellowgreenlasers AT qiany hostexcitonconfinementforenhancedforstertransferblendgainmediayieldinghighlyefficientyellowgreenlasers AT sunc hostexcitonconfinementforenhancedforstertransferblendgainmediayieldinghighlyefficientyellowgreenlasers AT luerl hostexcitonconfinementforenhancedforstertransferblendgainmediayieldinghighlyefficientyellowgreenlasers AT cabanillasgonzalezj hostexcitonconfinementforenhancedforstertransferblendgainmediayieldinghighlyefficientyellowgreenlasers AT bradleyd hostexcitonconfinementforenhancedforstertransferblendgainmediayieldinghighlyefficientyellowgreenlasers AT huangw hostexcitonconfinementforenhancedforstertransferblendgainmediayieldinghighlyefficientyellowgreenlasers |