The Electron-Transporting Behaviors of Low-Molecular-Weight P(NDI2OD-T2) and Polystyrene Blends

Abstract

To optimize the performance of low-molecular-weight poly{[N,N’-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5’-(2,2’-bithiophene)} [P(NDI2OD-T2)] as an electron-transporting layer material, the electron-transporting behavior of P(NDI2OD-T2) in blends with polystyrene (PSt) was investigated. The results demonstrated that blends of P(NDI2OD-T2) with 10 wt% PSt after annealing exhibited significantly higher electron-transporting performance compared to unblended P(NDI2OD-T2). The electron mobility of the annealed blends reached 3.26 × 10^-4 cm²/V·s, approximately 30 times higher than that of annealed unblended P(NDI2OD-T2) (1.08 × 10^-5 cm²/V·s) and about 100 times higher than that of unannealed unblended P(NDI2OD-T2) (2.95 × 10^-6 cm²/V·s). This enhanced performance is attributed to changes in the aggregate state and phase separation, particularly influenced by the unique properties of low-molecular-weight P(NDI2OD-T2) in facilitating uniform film formation and phase stability.