Among the most promising devices in the field of solar cells are nanocrystal-sensitized solar cells, inorganic nanocrystalline solid-state solar cells and hybrid solar cells. Current research in photovoltaics is focused on offering sustainable and real technologies. This means that the photovoltaic devices should be made of semiconductors with high affinity to the environment. This work investigates the structural, morphological, and optical properties between Cu2FeSnS4 (CFTS) and conducting polymers derived from polythiophene.

First, quaternary chalcogenide nanoparticles of CFTS are prepared by a microwave-assisted method. The polythiophene and poly(3-hexylthiophene) thin films are prepared by electrochemical methods on ITO substrates. The CFTS nanoparticles are deposited on the thin polymer films by screen printing. The structural, morphological and optical properties of the obtained hybrid thin films were characterized by Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDS), ultraviolet-visible spectroscopy (UV-Vis) and photoluminescence spectroscopy (PL). A flower-like morphology is obtained for the CFTS nanoparticles with a diameter of ~3.11±0.75 μm, consisting of nanosheets with a length of ~543±79.51 nm and ~28±3.76 nm. While the polymers exhibit absorption in the visible region, these bands are associated with the π → π* transition, which is due to the crystalline π-π stacking structure of the polymer. On the other hand, the emission spectra show a red-shifted behavior. The hybrid thin films show an enhancement of the optical absorption in the visible region due to the interface between the CFTS nanoparticles and the p-type polymers.