Open AccessConcurrent Optical Gain Optimization and Electrical Tuning in Novel Oligomer:Polymer Blends with Yellow‐Green Laser Emission
Author(s) -
Zhang Qi,
Wei Qi,
Guo Xiangru,
Hai Gang,
Sun Huizhi,
Li Jiewei,
Xia Ruidong,
Qian Yan,
Casado Santiago,
CastroSmirnov José Raúl,
CabanillasGonzalez Juan
Publication year - 2019
Publication title -
advanced science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.388
H-Index - 100
ISSN - 2198-3844
DOI - 10.1002/advs.201801455
Subject(s) - oligomer , materials science , polymer , laser , optoelectronics , green light , chemical engineering , composite material , polymer chemistry , optics , blue light , physics , engineering
Electrically pumped organic lasing requires the integration of electrodes contact into the laser cavity in an organic light‐emitting diode (OLED) or organic field effect transistor configuration to enable charge injection. Efficient and balanced carrier injection requires in turn alignment of the energy levels of the organic active layers with the Fermi levels of the cathode and anode. This can be achieved through chemical substitution with specific aromatic functional groups, although paying the price for a substantial (and often detrimental) change in the emission and light amplifying properties of the organic gain medium. Here, using host–guest energy transfer mixtures with hosts bearing a systematic and gradual shift in molecular orbitals is proposed, which reduces the amplified spontaneous emission (ASE) threshold of the organic gain medium significantly while leaving the peak emission unaffected. By virtue of the low guest doping required for complete host‐to‐guest energy transfer, the injection levels in the blends are attributed to the host whereas the gain properties solely depend on the guest. It is demonstrated that the ASE peak and thresholds of blends with different hosts do not differ while the current efficiency of OLEDs devices is deeply influenced by molecular orbital tuning of the hosts.