The paper presents the results of studying the influence of the environment on the surface structure, optical and electrical characteristics of the PEDOT:PSS film. The studies have been carried out in three different types of atmosphere under the same conditions of thermal annealing of the films. It has been established that the modification of the surface of a polymer film with ethanol and isopropanol in vacuum, in a nitrogen atmosphere, and in the air atmosphere leads to a change in the surface morphology and the optical electric transport properties of the polymer. Depending on the environment, when the PEDOT:PSS film is modified with a certain concentration of ethyl and isopropyl alcohols, the absorption spectra show a shift in the absorption maximum responsible for PEDOT to the short-wavelength region of the spectrum, as well as a decrease in the absorption peak of the part of the spectrum responsible for the absorption of the aromatic fragment PSS. It is identified that the structural features of the PEDOT:PSS surface morphology affect the electrical transport parameters of the films: Rh is the resistance of the PEDOT:PSS polymer film, Rext is the charge carrier transfer resistance at the PEDOT:PSS/electrode interface, keff is the effective charge carrier extraction rate and τeff is the effective transit time of charge carriers. The optimal technological parameters for film production have been determined, at which the electrical transport properties of PEDOT:PSS polymer films are increased.

The paper presents the results of studies of the effect of tungsten disulfide nanoparticles on the optical and electrotransport characteristics of PEDOT: PSS thin films in polymer solar cells. Tungsten disulfide (WS2) nanoparticles were obtained by laser ablation in isopropyl alcohol. The average size of nanoparticles were determined by dynamic light scattering and is ~38 nm. The concentration of WS2 nanoparticles in the solution was calculated based on the density of the WS2 substance. The absorption spectrum of nanoparticles in isopropyl alcohol has been measured. Two bands are observed in 500-900 nm regions, which are associated with direct exciton transitions A1 and B1 in two-dimensional transition metal dichalcogenides with 2H phase. WS2 nanoparticles were added in PEDOT: PSS solution and thin films were deposited from the prepared solution by spin-coating. PEDOT: PSS thin films doped with WS2 were studied by atomic force microscopy (AFM). The arithmetic mean deviation of the surface roughness (Ra) was estimated. Doping with WS2 nanoparticles leads to the increase in Ra of PEDOT: PSS thin films. The optical absorption spectra of doped films have been measured. Also, doping PEDOT: PSS with WS2 nanoparticles results in a long-wavelength shift of the PEDOT absorption maximum. The optimal concentration of WS2 nanoparticles for the preparation of doped PEDOT: PSS thin films is determined, at which the film resistance decreases by almost 2 times, the recombination resistance of charge carriers increases by 4.7 times, and the efficiency of the polymer solar cell increases to 1.94 %.