Water-processable nanocomposite based on polyaniline and 2D molybdenum disulfide for NIR-transparent ambipolar transport layers

Polymer nanocomposite based on stable water-dispersible polyaniline complex with poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PANI–PAMPSA) and 2D molybdenum disulphide (MoS₂) was developed. The nanocomposite layers obtained by drop-casting were characterized by Vis–NIR- and FTIR spectroscopies, as well as by atomic force, transmission electron, and Kelvin-probe microscopies, X-ray diffraction, cyclic voltammetry, Hall effect, and DC-conductivity measurements. It was shown that the preparation procedure allows easy adjusting of MoS₂ content in the nanocomposite resulting in the growth of DC conductivity by up to six times in the case of 20 wt% MoS₂ as compared with the additive-free PANI–PAMPSA complex. FTIR spectroscopy revealed the existence of hydrophobic interactions between PANI–PAMPSA and 2D MoS₂ nanophase, which facilitate interchain electron transfer. Hall effect studies showed that while increasing MoS₂ content in the nanocomposite, a transition occurs from monopolar hole transport, characteristic of PANI–PAMPSA, to ambipolar transport. This feature makes the obtained PANI–PAMPSA/MoS₂ composite a promising material for different optoelectronic devices, in particular tandem solar cells.