TY - JOUR
T1 - Enhanced Energy Transfer in Doped Bifluorene Single Crystals
T2 - Prospects for Organic Lasers
AU - Baronas, Paulius
AU - Kreiza, Gediminas
AU - Mamada, Masashi
AU - Maedera, Satoshi
AU - Adomėnas, Povilas
AU - Adomėnienė, Ona
AU - Kazlauskas, Karolis
AU - Adachi, Chihaya
AU - Juršėnas, Saulius
N1 - Funding Information:
This project has received funding from European Social Fund (Project No. 09.3.3-LMT-K-718-01-0026) under grant agreement with the Research Council of Lithuania (LMTLT). It has been supported in part by The Japan Science and Technology Agency (JST), ERATO, Adachi Molecular Exciton Engineering Project (Grant No. JPMJER1305). The authors thank Dr. Sandra Stanionytė for carrying out XRD measurements.
Publisher Copyright:
© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2020/2/1
Y1 - 2020/2/1
N2 - Organic single crystals with long-range molecular order ensure enhanced carrier mobility and stability as well as emission outcoupling, which makes them attractive as gain medium for electrically pumped organic lasers. Unfortunately, effects of excitonic coupling introduce losses degrading optical performance in crystals, hence higher lasing thresholds are observed compared to amorphous films. Here, crystal doping strategy is investigated as a method to avoid pronounced reabsorption and annihilation losses associated with J-type excitonic coupling, while taking advantage of enhanced exciton transport for efficient energy transfer. Bifluorene-based derivatives linked with acetylene and ethylene rigid bridges are suitable as host and dopant system forming high-quality crystals doped at various concentrations (0.5–11.0%). Enhanced exciton transport in host crystal mediates picosecond host–dopant energy transfer enabling 100% transfer efficiency at lower doping concentrations compared to amorphous films. Amplified spontaneous emission threshold of 1.9 µJ cm−2 in 3.5% doped crystal is enabled by minimized exciton annihilation and emission reabsorption losses at optimal doping concentration.
AB - Organic single crystals with long-range molecular order ensure enhanced carrier mobility and stability as well as emission outcoupling, which makes them attractive as gain medium for electrically pumped organic lasers. Unfortunately, effects of excitonic coupling introduce losses degrading optical performance in crystals, hence higher lasing thresholds are observed compared to amorphous films. Here, crystal doping strategy is investigated as a method to avoid pronounced reabsorption and annihilation losses associated with J-type excitonic coupling, while taking advantage of enhanced exciton transport for efficient energy transfer. Bifluorene-based derivatives linked with acetylene and ethylene rigid bridges are suitable as host and dopant system forming high-quality crystals doped at various concentrations (0.5–11.0%). Enhanced exciton transport in host crystal mediates picosecond host–dopant energy transfer enabling 100% transfer efficiency at lower doping concentrations compared to amorphous films. Amplified spontaneous emission threshold of 1.9 µJ cm−2 in 3.5% doped crystal is enabled by minimized exciton annihilation and emission reabsorption losses at optimal doping concentration.
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U2 - 10.1002/adom.201901670
DO - 10.1002/adom.201901670
M3 - Article
AN - SCOPUS:85076349119
SN - 2195-1071
VL - 8
JO - Advanced Optical Materials
JF - Advanced Optical Materials
IS - 4
M1 - 1901670
ER -