Apr 8, 2025
1:45pm - 2:15pm
Summit, Level 4, Room 427
Thuc-Quyen Nguyen1
University of California, Santa Barbara1
Shortwave infrared (SWIR) has various applications, including night vision, remote sensing, and medical imaging. SWIR organic photodetectors (OPDs) offer advantages such as flexibility, cost-effectiveness, and tunable properties, however, lower sensitivity and limited spectral coverage compared to inorganic counterparts are major drawbacks. In the process of implementing OPDs into well-established Si-based manufacturing process, organic semiconductors are subjected to high temperature up to 200 C, which results in deterioration of photosensing capability due to the undesirable morphological changes. The underlying morphology-stability-property relationships are difficult to establish, owing to the compositional and structural heterogeneities associated with the OPDs. Here, we combine multiscale characterization and device physics to unravel the impact of thermal stress on the optoelectronics characteristics of polymer donor:non-fullerene acceptor blends. Our results indicate that reduction in the efficiency of OPDs under thermal annealing (200 C for 5-120 minutes) is observed due to the morphological degradation, regardless of the NFA choice, but is more severe for some blends. Thermally induced morphological changes are examined using atomic-force microscopy, wide-angle X-ray scattering and solid-state NMR spectroscopy. This study provides essential insights into morphology-driven deteriorations, which will help in developing structure-stability-performance relationships in high detectivity OPDs.