Poly(o-phenylenediamine) thin film for organic solar cell applications

Poly(ortho phenylenediamine) (PoPDA) microrods with ladder-type structure are synthesized in acidic medium (pH = 0.5) at room temperature based on a developed and facile method. The molecular structure, thermal stability, and surface morphology of the microrods-shaped PoPDA were described by different characterization techniques comprising FTIR, TGA, 1HNMR, and SEM. Optimized thin films of PoPDA were successfully fabricated by thermal deposition method. The thin film was characterized by XRD and AFM. Au/PoPDA/p-Si/Al heterojunction diodes have been successfully fabricated. Dark current–voltage and capacitance–voltage characteristics were applied to get the particular parameters of the devices. Photovoltaic features of Au/PoPDA/p-Si/Al heterojunction at various intensities of white light illumination are studied. Under optimized conditions, the fabricated planar heterojunction solar cells utilizing a 95 ± 10 nm of PoPDA film exhibited a power conversion efficiency (PCE) of ~ 5.64% (JSC = 41.78 A/m2, VOC = 0.36 V, and FF = 28.11%). The relatively small FF (at room temperature with IP) and Rs of the devices designate that by increasing of the absolute temperature, the photovoltaic performance of the solar cells can be improved.