Solution-Processed PEDOT:PSS/MoS2 Nanocomposites as Efficient Hole-Transporting Layers for Organic Solar Cells.

ABSTRACT

An efficient hole-transporting layer (HTL) based on functionalized two-dimensional (2D) MoS2-poly(3,4-ethylenedioxythiophene)poly(styrenesulfonate) (PEDOTPSS) composites has been developed for use in organic solar cells (OSCs). Few-layer, oleylamine-functionalized MoS2 (FMoS2) nanosheets were prepared via a simple and cost-effective solution-phase exfoliation method; then, they were blended into PEDOTPSS, a conducting conjugated polymer, and the resulting hybrid film (PEDOTPSS/FMoS2) was tested as an HTL for poly(3-hexylthiophene)[6,6]-phenyl-C61-butyric acid methyl ester (P3HTPCBM) OSCs. The devices using this hybrid film HTL showed power conversion efficiencies up to 3.74%, which is 15.08% higher than that of the reference ones having PEDOTPSS as HTL. Atomic force microscopy and contact angle measurements confirmed the compatibility of the PEDOTPSS/FMoS2 surface for active layer deposition on it. The electrical impedance spectroscopy analysis revealed that their use minimized the charge-transfer resistance of the OSCs, consequently improving their performance compared with the reference cells. Thus, the proposed fabrication of such HTLs incorporating 2D nanomaterials could be further expanded as a universal protocol for various high-performance optoelectronic devices.