نبذة مختصرة : International audience ; ZnO is an intrinsic n-type semiconductor and one of the most widely studied semiconductors [1]. The high exciton binding energy of 60 meV and wide band gap of 3.37 eV of ZnO make it a promising material for various applications in photovoltaics, light emitting diodes, ultra-violet (UV) sensors, UV lasers, and photo detectors [2]. Depending on the synthesis conditions, various nanostructures of ZnO can be grown including nanoparticles, nanorods, nanobelts, nanowires, nanoflowers… The high surface to volume ratio of such nanostructures offers advantages in various optoelectronic and sensing applications. When combined with p-type Poly(3,4 ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), a hybrid inorganic-organic p-n junction is created [3]. In addition, the high leakage current is lowered by adding an insulating polymer such as Poly(9,9-dioctylfluorene-alt-benzothiadiazole) (F8BT) in between ZnO and PEDOT:PSS. In this study, we investigated the effect of different seeding solvents (methanol, ethanol, isopropanol and 70% aqueous ethanol) on the physical, optical and electrical properties of ZnO nanorods and their combination with PEDOT:PSS and F8BT polymers. The ZnO nanorods were grown on different types of seeding layers preliminary deposited on etched ITO substrate via a hydrothermal process. The X-ray diffraction studies of these nanorods indicated growth along the c-axis of ZnO. The photoluminescence study revealed various surface and volume defects in ZnO nanorods. The UV response study of bare ZnO nanorods exhibited variations in the decay time. A persistent conductivity of ZnO nanorods after the removal of UV excitation was also observed. For the fabrication of p-n heterojunctions, ZnO nanorods grown were spin-coated with F8BT and PEDOT:PSS polymers. The I-V characteristics of the heterojunctions were characterized by Ag Schottky contacts on top of the PEDOT:PSS layer. The device showed diode-like characteristics with an ideality factor of ~5.5. In addition, the ...
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