Abstract A ladder polysilsesquioxanes with side chain of dibenzothiophene groups (BS- LPSQ) was successfully synthesized. The ladder structure of BS-LPSQ was characterized by MALDI-TOF MS, XRD, and 1 H NMR spectroscopy. Differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), atomic force microscopy (AFM), and spectroscopic analyses revealed that the BS-LPSQ has good film-forming ability, high thermal and ...