Designing Poly(arylene ether sulfone)s with Platinum(II) Acetylide to Regulate Photophysical Properties toward Solid-State Nonlinear Limiters

Abstract

The exploration of solid-state optical power limiting (OPL) materials based on nonlinear absorption (NLA) with heat resistance is essential and leading-edge. We present two types of poly(arylene ether sulfone)s (PAESs) derived from platinum acetylide, featuring varying conjugation lengths and platinum contents. The platinum-incorporated PAESs exhibit outstanding thermal properties (T g > 180 °C, T d5% ≥ 400 °C) with easy processing into solid films from solvents. Photophysics, ultrafast transient absorption, Z-scan characterizations, and theoretical calculations reveal an abnormal intersystem crossing and the principle of triplet nonlinear limiting (S 0 → S 1 → T x → T 1 → T n ). The extended τ P caused by the longer conjugated ligand is more critical for NLA compared with the lower Φ P caused by higher Pt contents. PAESs with a longer conjugated ligand exhibit superior intrinsic NLA under limited platinum content, while those with shorter conjugated ligands strike a balance between transparency and NLA. The optical limiting threshold (F th ) of the solid-state film is as low as 1.86 J/cm 2 . This study involves the preparation of solid-state OPL films using platinum-modified PAESs, revealing an intrinsic link between structure and optical properties.