Checkmate: Self-assembled nanowires produce robust deep-blue emission

Efficient and stable deep-blue, light-emitting optoelectronic devices based on wide bandgap light-emitting conjugated polymers (LCPs) have applications in polymer light-emitting diodes (PLEDs) and polymer lasers.

And researches from Exciton Science, in collaboration with partner institutions in China, have demonstrated self-assembled polydiarylfluorene-based (P8DPF) crystalline LCP nanowires with robust deep-blue emission behaviour. 

Efficient PLEDs and a nano-laser based on the self-assembled nanowires as the luminescent medium were demonstrated. 

The time-resolved photoluminescence and fluorescence anisotropy microscopy methods that have been developed in the Ultrafast and Microspectroscopy Labs at The University of Melbourne were applied to probe films of the crystalline nanowires compared to the crystalline β-conformation and amorphous forms of P8DPF.  

Significant differences in the emission decay and energy migration properties of these films confirmed that the P8DPF nanowires exhibit a high-quality, hierarchical, well-defined crystalline structure and anisotropic emission, which provides the potential as a gain medium for electrically pumped organic lasers.

The paper “Hierarchical Uniform Crystalline Nanowires of Wide Bandgap Conjugated Polymer for Light-Emitting Optoelectronic Devices” resulted from a collaboration between several groups in China (from Nanjing and Xi’an) and members of The University of Melburne node of Exciton Science, PhD student Hamid Soleimaninejad and Chief Investigators Trevor Smith and Ken Ghiggino.  

The paper can be reviewed in full in the journal Cell Reports Physical Science here.