The effect of molybdenum disulfide nanoparticles on the properties zinc oxide electron transport layer of organic solar cells

Abstract

In this work, the effect of molybdenum disulfide nanoparticles on the properties zinc oxide electron transport layer of organic solar cells is studied. molybdenum disulfide nanoparticles were obtained by laser ablation of MoS2 powder in isopropyl alcohol. To form composite films, nanoparticles were added to a sol–gel zinc oxide solution with different concentrations. According to scanning electron microscope study, as the concentration of nanoparticles in the film increases, the thickness of the molybdenum disulfide layer on the zinc oxide surface changes. molybdenum disulfide nanoparticles in the film structure gradually fill the bulk and surface voids in zinc oxide. However, when the concentration exceeds 1%, holes and voids are formed in the film. The absorption spectra of composite films showed that as the concentration of nanoparticles in the film increases, the absorption intensity enhances due to the increase of the overall thickness. At the same time, zinc oxide optical band gap width does not change, which means the molybdenum disulfide nanoparticles do not affect the electronic structure of zinc oxide. It was shown that the observed changes in the volt-ampere characteristic of organic solar cells with composite films electron transport layer composite films was associated with the influence of molybdenum disulfide nanoparticles on electron transport in organic solar cells. According to impedance spectroscopy study, it was found that molybdenum disulfide nanoparticles at concentration below critical value increases the lifetime of charge carriers and the diffusion coefficient in composite film.