Ladder polysilsesquioxane for wide-band semiconductors: synthesis, optical properties and doped electrophosphorescent device

A ladder polysilsesquioxane with side chain 3-methyl-1,5-diphenylbenzene groups (Tp-LPSQ) is synthesized successfully and confirmed by the MALDI-TOF MS, 29Si-NMR and 1H-NMR. DSC, TGA, AFM and PL spectra reveal its good film-forming property, high thermal and morphological stability and good miscibility to the dopant FIrpic. In addition, it also shows a high triplet energy and a wide bandgap. Thus Tp-LPSQ may act as a host for the blue light emitting iridium complex FIrpic. The electrophosphorescent device based on Tp-LPSQ as the active layer exhibits typical blue emission and the performance of device is superior to other reported polymeric host materials.