Influence of the volume of EGME-DMSO mixed co-solvent doping on the characteristics of PEDOT:PSS and their application in polymer solar cells

Abstract

Poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate) (PEDOT:PSS) is one of the most widely used hole transport layer (HTL) in polymer solar cells (PSCs). However, the improving of the conductivity and transparency of PEDOT:PSS thin films is still needed. To solve this problem, we here introduce 2-methoxyethanol (EGME) and dimethyl sulfoxide (DMSO) mixed secondary solvent to PEDOT:PSS solution as a novel additive to the best of our knowledge. We determined that the EGME-DMSO doped PEDOT:PSS layer provides better energy level alignment, conductivity and morphology with the help of methods of UV-Vis spectroscopy, atomic force microscopy, etc. The addition of 15% (v/v.) volume of EGME-DMSO mixed co-solvent improves the efficiency from 2.8% of control device to 3.9%. The significant enhancement of the short-circuit current density (Jsc) of 13.7 to 16.5 mA cm−2 is the main reason for this increase of performance due to better charge transport properties. This suggests that the EGME-DMSO mixed co-solvent doping into PEDOT:PSS solution is a simple approach to fabricate highly efficient PSCs.

Recent Advances in Hole-Transporting Layers for Organic Solar Cells

“…PEDOT:PSS treatment with solvents as isopropanol (IPA) also shows a better performance, mainly due to more uniform morphology, increased J SC , and improved cell-light absorption [ 260 ]. 2-Methoxyethanol (EGME) and dimethyl sulfoxide (DMSO) solvents were added to a PEDOT:PSS solution [ 261 ]. The conductivity after doping was about seven times higher and the OSCs based on P3HT:PCBM improved the PCE from 2.8% to 3.9% owing to increased J sc 16.5 mA cm −2 and FF of 38.0%.…”

PEDOT:PSS, TiO2 Nanoparticles, and Carbon Quantum Dot Composites as Ultraviolet Sensors

“…So, 365 nm wavelength was the optimized UV range. The UV–vis and PL spectra were also done for bare CQDs, and the absorption and PL were observed at 440 and 450 nm, respectively, giving out a blue color emission as shown in Figure S4 . X-ray photoelectron spectroscopy (XPS) was carried out for PEDOT:PSS to find the surface elemental composition and bonding, as shown in Figure S5.…”

“…The UV−vis and PL spectra were also done for bare CQDs, and the absorption and PL were observed at 440 and 450 nm, respectively, giving out a blue color emission as shown in Figure S4. 56 X-ray photoelectron spectroscopy (XPS) was carried out for PEDOT:PSS to find the surface elemental composition and bonding, as shown in Figure S5. The carbon spectra (C 1s) are shown in Figure S5a, where the peak at 282.5 eV depicts the C�C chain of α-PEDOT, and the peak at 283.6 eV is attributed to the C−O−C chain.…”