Conjugated Nanopolymer Based on a Nanogrid: Approach toward Stable Polyfluorene-Type Fluorescent Emitter for Blue Polymer Light-Emitting Diodes

Although the performance of organic semiconductor devices has reached the standard of commercial products after several decades of development, the stability of organic semiconducting materials remains a key factor that severely impedes the long-term operation of organic electronics in the practical applications. In this study, a conjugated nanopolymer based on a nanogrid was synthesized and systematically examined, and it was compared with two other types of polyfluorenes in terms of the stability, including thermal, spectral, morphological, and electroluminescent stability. These results reveal that the grid structure in PG-C8 nanopolymer not only enables higher thermal and spectral stability but also provides better morphology stability and electroluminescent stability than traditional linear polyfluorene PFO and polyfluorene PH with nongrid steric hindrance. Therefore, research into optimized nanogrid-based nanopolymers can be an effective strategy for obtaining comprehensively ultrastable materials and devices for plastic electronics.