Triazine,Pyrene,Triphenylamine Derivatives As Gain Media For Organic Lasers

With many fanscinating advantages such as high solid-state photoluminescence quantum yield(PLQY), large absorption and emission cross-section, and tunable optoelectronic properties, organic gain semiconductors have gain more and more interest. Although much progress has been achieved since the first demonstration of optically-pumped organic solid-state laser(OSSL) in 1996, realization of the electrically-dirven OSSLs still remains a worldwide challenge. Much work has been focused on material development and device structure innovation. With the consensus that material innovation is very crucial for the demonstration of electrically-pumped OSSL, our group has developed several series of high-performance gain materials based on triazine, pyrene, and triphenylamine units. In the present work, detailed characterizations as well as improving strategies have been carried out for these new materials to deeply understand the optoelectronic properties and therefore broaden the application prospect in the field of OSSLs.(1) Basic photophysical characterizations, such as UV-vis spectra and photoluminescence(PL) spectra, and standard amplified spontaneous emission(ASE) measurements have been used to assess the role of triazine unit in improving the optical gain properties for the new class materials(C1, C2, 2FCz and 4FCz) with/without triazine units. Thermal stability and optical stability tests have been conducted to assess the application prospect of the trizine derivatives in OSSLs. Polystyrene(PS) dopping project has been taken to further improve the thermal stability of C2 while keeping the overall ASE properties.(2) A new class of materials(SF-PyF and Py-PyF) based on spirofluorene and pyrene units with excellent stability have been developed following the material design principle, and basic photophysical characterizations have been used to explore the role of spirofluorene and pyrene units in photophysical properites. The results of thermal and electrical stability tests show that the two gain materials has superior ambient stability. The DFB lasers incorporated with SF-PyF and Py-PyF exhibit relatively good lasing performance. Moreover, the laser devices can stably and continuously operate even under hot water conditions for a long time.(3) The solvent effects of triphenylamine derivative, TPAOH with amphipathicity, on the absorption and PL spectra have been detailedly investigated. The results of morphology characterizations show that the surface topography is closely related with organic solvents. And moreover, the ASE actions of TPAOH films have strong dependence on the morphologies induced by the solvent effects. TPAOH, as interfacial layer, has been introduced beteween the metallic electrode and gain media layer, and the outcome shows that TPAOH has a relatively positive role in the ASE restoration and threshold reduction for the laser device.