POS6-1412
Spectral Gap-Filling Pt(NHC-phenoxo)₂ Sensitizer suppresses Triplet Recombination in High-Performance D-A-A-D Ternary OSCs
When and Where
Nov 30, -0001
00:00 - 00:00
Room 301 (Grand Ballroom)
Presenter(s)
Priyanka Yadav (Pusan National University)
Co-Author(s)
Abstract
In this study, we report a newly developed D-A-A-D-type polymer donor (DAAD-OMe) exhibiting a film absorption peak at 559 nm and an optical bandgap of 1.75 eV. Complementary absorption profiles and favorable energy level offsets were established among the PM6 host, DAAD-OMe guest donor, and L8-BO acceptor in an inverted device architecture. The ternary active layer was phosphor-sensitized with 1 wt.% Py_Pt-2, a square-planar Pt(NHC-phenoxo)₂ complex (λmax = 496 nm, HOMO/LUMO = -5.36/-2.72 eV, Eg = 2.64 eV), processed via a dual-solvent strategy. The optimized inverted ternary device achieved a record PCE of 18.7% (Voc = 0.89 V, Jsc = 27.6 mA cm⁻², FF = 76.3%), a 7.8% relative improvement over the undoped binary control (16.8%). Py_Pt-2 provides ideal energy-level alignment for efficient triplet energy transfer (³MLCT → DAAD-OMe singlet) while filling the critical 400-500 nm spectral absorption gap. The phosphorescent dopant simultaneously suppresses non-radiative recombination, boosting Voc, and enhances charge generation, improving FF. Morphological studies reveal uniform phase separation with suppressed triplet quenching, while the high glass transition temperature of DAAD-OMe (Tg = 174 °C) ensures operational stability exceeding 1000 h under accelerated aging. These results establish DAAD-OMe as a powerful donor polymer and Py_Pt-2 as a promising phosphor-sensitizer for next-generation high-efficiency, durable OSCs
