Analysis of charge transfer and recombination for the poly(3-hexylthiophene):[6,6]-phenyl C_(61) butyric acid methyl ester organic solar cells with iron oxide nanoparticles in various layers

摘要

An improved organic solar cell's performance was obtained by focusing on the effects of iron oxide (Fe_2O_3) nanoparticles (NPs) within the different layers of P3HT:PCBM solar cells. We investigated the recombination mechanism in organic solar cells using the current density-voltage (J-V) characteristics at various light intensities and also analyzed the electrochemical impedance. Shockley-Read-Hall (SRH) recombination, which is dependent on the trap states, surface roughness, resistance and charge transport, controls the cell efficiency. The device performance was compared by adding iron oxide nanoparticles in the active layer and Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) layer, respectively. Also the iron oxide nanoparticle layer was inserted as an interface layer between active and PEDOT:PSS layers. The solar cell without NPs showed a 2.68% power conversion efficiency while that with Fe_2O_3 NPs as an interface layer showed a higher power conversion efficiency of 3.83% under air mass (AM) 1.5G illumination. The device with NPs as an interface layer showed a smooth surface roughness (1.16 nm), lower charge recombination (1.06(kT/e)), and lower parasitic resistance (254 Ω cm~2).