Solution-processed polyfluorene:Naphthalenediimide-n-doped TiO 2 hybrids for ultraviolet photodetector applications

In this study, highly efficient ultraviolet (UV) photodetectors based on a solution-processed system are introduced. Nitrogen-doped TiO 2 nanoparticles are embedded in poly(9,9-dioctylfluorenyl-2,7-yleneethynylene) (PFE):N,N'-bis-n-butyl-1,4,5,8-naphthalenediimide (BNDI) (3:1 wt.%) blends. An UV- active layer of [(PFE:BNDI)(3:1):ammonium hydroxide-TiO 2 ] [9:1 wt.%] gave a photoresponsivity value of 545 ± 6.92 mA/W at -4 V under 1 mW/cm 2 UV light at 365 nm, and this value was increased to 597 ± 9.22 mA/W on annealing the active layer at 60 C. The efficiencies obtained are strongly dependent on the nitrogen source nature, their donor-acceptor relationship, and the morphological interaction with the PFE:BNDI blend. © 2013 TMS