Solution Processed WO3 and PEDOT:PSS Composite for Hole Transport Layer in ITO-Free Organic Solar Cells

• Published in: Journal of cluster science 2023-07, Vol.34 (4), p.2135-2145
• Main Authors: Gurudevi, P., Venkateswari, P., Sivakumar, T., Ramesh, C., Vanitha, P.
• Format: Article
• Language: English
• Subjects: Aqueous solutions; Catalysis; Chemistry; Chemistry and Materials Science; Current leakage; Electrodes; Glass substrates; Indium; Inorganic Chemistry; Luminous intensity; Nanochemistry; Nanocomposites; Original Paper; Photoelectrons; Photovoltaic cells; Physical Chemistry; Polymers; Scanning electron microscopy; Solar cells; Solvents; Spectrum analysis; Thin films; Tungsten oxides; X ray photoelectron spectroscopy; X-ray diffraction
• ISSN: 1040-7278; 1572-8862
• DOI: 10.1007/s10876-022-02368-6

We developed PEDOT:PSS [poly (styrenesulfonate)-doped poly(3,4-ethylenedioxythiophene] and tungsten oxide (WO 3 ) based hybrid thin films by facile hydrothermal method. The solution processed WO 3 –PEDOT:PSS hybrid thin films are fully characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), UV–Vis (UV), Raman, X-ray photoelectron spectra (XPS) and Brunauer–Emmett–Teller (BET) surface area analysis. XRD and SEM results suggest that WO 3 has crystalline structure with monoclinic phase and spherical shaped nanoparticles (20–25 nm), which is uniformly decorated on the surface of PEDOT:PSS sheets. The value of E g [calculated by linear extrapolating of (F(R ∞) hν) 2 and hν] was evaluated to be 3.11 and 2.85 eV for pure WO 3 and WO 3 /PEDOT:PSS, respectively. The PL intensity of WO 3 /PEDOT:PSS is maximum lower than the pristine WO 3 and PEDOT:PSS, implying an improved interfacial contact quality at the WO 3 /PEDOT:PSS. Photovoltaic performance of WO 3 –PEDOT:PSS devices were measured under AM 1.5 G 1 sun light intensity of 100 mW/cm 2 . Organic solar cell devices with WO 3 –PEDOT:PSS layer give rise to a significant increase in J SC from 9.35 ± 0.03 to 16.2 ± 0.01 mA/cm 2 respectively and in V OC from 0.28 V to 0.72 V respectively, resulting in a remarkable PCE increase from 0.592 ± 0.03 to 0.714 ± 0.02%. The WO 3 /PEDOT:PSS composite deliver a PCE of 7.81 ± 0.01%. The superior performance of WO 3 /PEDOT:PSS composite was attributed to the reduced current leakage, enhanced hole extraction characteristics, and less trap-assisted interfacial recombination via current density–voltage.