Bulk heterojunction organic photovoltaic devices containing silicon phthalocyanine as a non-fullerene electron acceptor

Silicon phthalocyanines have been identified as a potential non-fullerene electron acceptor in organic photovoltaics. Bis(tri-n-butylsilyl oxide) silicon phthalocyanine ((3BS)2-SiPc) is shown to be a direct replacement for phenyl-C61-butyric acid methyl ester (PC61BM) with poly(3-hexylthiophene) (P3HT) in bulk heterojunction organic photovoltaics. Devices fabricated with a P3HT:(3BS)2-SiPc active layer displayed a power conversion efficiency (PCE) of 3.6% alongside a Voc of 0.76 V. These novel devices exhibited higher PCEs over a wide range of incident angles and light intensities, while also operating at longer wavelengths compared to devices with a P3HT:PC61BM active layer. This merits future investigation into commercial applications.