Planar heterojunction organic photodetectors with enhanced air stability
발표자
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초록
내용
Despite their high performance, bulk-heterojunction (BHJ) organic photodiodes (OPDs) often suffer from reduced air stability due to unstable nanomorphology in photoactive layers. In this work, we demonstrate that using immiscible electron donor/acceptor planar heterojunction (PHJ) photoactive bilayers can significantly enhance the air stability of OPDs. We employed the thiophene-based copolymer RP-T50, featuring thermocleavable alkyl side chains, as the electron donor material. Thermally annealed RP-T50 thin films form well-defined interfaces with the adjacent [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) electron acceptor layers. Consequently, OPDs with RP-T50/PC71BM photoactive bilayers exhibit markedly enhanced air stability compared to conventional poly(3-hexylthiophene) (P3HT)-based OPDs. This enhancement is attributed to the immiscible RP-T50/PC71BM interface, which avoids the pseudo-BHJ structures typically observed in the slightly mixed P3HT/PC71BM bilayers.