Organic Semiconductor Building Blocks with Benzoxadiazole Core

Naphtho[1,2-c:5,6-c']bis([1,2,5]oxadiazole) (NOz) analogs (1-3) are used as electron-acceptor type building blocks for the constructing organic semiconductors. They are more electron-deficient compared to the naphtho[1,2-c:5,6-c']bis([1,2,5]thiadiazole) (NTz) analogs. Donor-acceptor conjugated polymers containing the NOz structures are expected to have deeper HOMO and LUMO levels than those of the NTz-based polymers. In fact, it has been reported that a donor-acceptor conjugated polymer (PNOz4T) and subsequently deep energy levels and high crystallinity, provides high hole mobility properties (μ_h = 0.55 cm²/Vs, on triethoxy-1H,1H,2H,2H-heptadecafluorodecylsilane-treated substrates) and ambipolar behavior (μ_h = 0.27 cm²/Vs and μ_e = 0.17 cm²/Vs, on octadecyltriethoxysilane-treated substrates).¹⁾