Correlation between materials and band‐selective detection in organic photodetectors based on bulk heterojunction

• Published in: Journal of applied polymer science 2024-06, Vol.141 (23), p.n/a
• Main Authors: Eynaud, Quentin, Khodr, Anass, Kramdi, Mohamed El Amine, Quéléver, Gilles, Margeat, Olivier, Ackermann, Jörg, Videlot‐Ackermann, Christine
• Format: Article
• Language: English
• Subjects: blends; Chemical Sciences; Heterojunctions; Material chemistry; optical and photovoltaic applications; optical properties; Photometers; Spectral sensitivity; Thickness
• ISSN: 0021-8995; 1097-4628
• DOI: 10.1002/app.55481

For wavelength‐selective photodetection or color discrimination, organic photodetectors (OPDs) can provide significant advantages as solution processability, chemical versatility and functionality. To eliminate the need for commonly used filters, the development of a narrowing approach that simultaneously achieves a selective detection range of less than 50 nm bandwidth and a spectral response of ~20% as efficiency at a required wavelength, remains a real challenge. Herein, different donor polymers and small acceptor molecules have been involved in bulk heterojunctions (BHJs) at 1:1 weight ratio as photoactive layers in specific OPDs. Indeed, the mechanism of charge collection in these OPDs is based on the charge collection narrowing (CCN) principle. In this approach, the detection window can be selected to match the absorption onset of the junction materials used in the BHJ layer. Although essentially based on very thick layers, we are focusing here on OPDs with layer thicknesses of less than 2 μm and post‐deposition annealing temperatures not in excess of 100°C. EQE spectra and corresponding BHJ absorption spectra of a highly wavelength‐selective OPD versus an OPD with spurious detection.