Enhanced Energy Transfer in Doped Bifluorene Single Crystals: Prospects for Organic Lasers

Paulius Baronas, Gediminas Kreiza, Masashi Mamada, Satoshi Maedera, Povilas Adomėnas, Ona Adomėnienė, Karolis Kazlauskas, Chihaya Adachi, Saulius Juršėnas

Research output: Contribution to journalArticlepeer-review

14 Citations (Scopus)


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.

Original languageEnglish
Article number1901670
JournalAdvanced Optical Materials
Issue number4
Publication statusPublished - Feb 1 2020

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics


Dive into the research topics of 'Enhanced Energy Transfer in Doped Bifluorene Single Crystals: Prospects for Organic Lasers'. Together they form a unique fingerprint.

Cite this