Thermally Robust Organic Photodetectors Enabled by Polymer Acceptors with Tunable Rigidity

Journal article, 2026

Organic photodetectors (OPDs) have emerged as promising candidates for next-generation optoelectronic applications. However, their widespread adoption is hindered by the low thermal stability. This study addresses this issue by investigating the performance of OPDs employing three polymer acceptors: PF5-Y5, PYTS-C2, and PY2TS-C2 paired with the PBDB-T polymer donor. These devices demonstrate significantly improved resistance to thermal stress. After annealing at 150 degrees C for 1 h, the PF5-Y5-based OPDs can maintain a dark current density (J(d)) below 1 & times; 10(-6) A/cm(2) and an external quantum efficiency (EQE) above 50%, leading to a specific detectivity of 1.7 & times; 10(11) Jones. Detailed analysis reveals that the EQE drop in the PF5-Y5-based OPDs is due to decreased electron mobility, and J(d) increases in the PY2TS-C2 and Y6 systems are attributed to enhanced aggregation and phase separation and C-60 and electrode diffusion. These results highlight the advantages of polymer acceptors in enhancing thermal robustness and provide design strategies for developing thermally stable OPDs.