Lutetium Bis(2,3,9,10,16,17,23,24-octafluorophthalocyanine): From Synthesis to Heterojunction Device

Lutetium bisphthalocyanine (LuPc 2 ) is a well-established molecular semiconductor, yet its fluorinated derivatives remain largely unexplored. In this work, we investigate the lutetium octafluorosubstituted bisphthalocyanine complex, Lu(F 8 Pc) 2 . The complex was synthesized both directly from 4,5-difluoro-1,2-dicyanobenzene and via the metal-free octafluorophthalocyanine precursor H 2 F 8 Pc, and characterized by mass spectrometry and optical spectroscopy. Drop-cast films of Lu(F 8 Pc) 2 were fabricated and their electrical properties evaluated. Additionally, we examined the response of these resistors to ammonia. Bilayer heterojunctions combining Lu(F 8 Pc) 2 with its nonsubstituted analogue, LuPc 2, were also prepared. Notably, Lu(F 8 Pc) 2 resistors and Lu(F 8 Pc) 2 /LuPc 2 heterojunctions exhibit opposite responses to NH 3, positive and negative, respectively. These findings provide new insights into structure–property relationships in phthalocyanine-based semiconductors.