Lead sulphide (PbS) thin films represent a direct band gap IV–VI p-type semiconductor material (Eg= 0.41 eV) and have a good potential application in solar cells, infrared detector devices, sensors, etc[1]. The electrical properties of PbS film can be tuned via doping with Cu2+ and Cd2+[2, 3]. These ions have good ability to substitute Pb2+ locations in the PbS crystal lattice, and thus tune its energy band gap. Also, the structural properties of the film, such as the grain size, can depend on the dopant concentration and will affect the PbS band gap and conductivity. These features are important for instance, when PbS film are applied as photoactive materials in solar cells[4]. Here we present an investigation on doping PbS thin films by Cu. Cu-doped PbS films were deposited on ordinary glass and conducting glass substrates through chemical bath deposition. The samples deposited on the F:SnO2 conducting layers were used for a high-resolution SEM measurements and scanning spreading resistance microscopy (SSRM) characterization using scanning probe microscopy (SPM). The morphology and topography of the doped PbS films were examined using tapping mode AFM (NT-MDT Ntegra) and high-resolution SEM (Magellan 400 XHR-SEM). The crystalline shape was triangular and did not change much with the dopant concentration increase from 0.5% to 2%. Films in the range 120 to 380 nm were considered. Good agreement was found between thickness measured through cross-section HR-SEM and Rutherford backscattering spectrometry (RBS). Also, the RBS investigation has shown that the film thickness tends to decrease for an increase of the dopant concentration. All the doped films seem having lower doping concentration, compared to the nominal one, as obtained from RBS analysis. XPS highlighted a Cu-enriched surface layer, possibly due to selective segregation of the doped films during their growth. Additionally, advanced electrical measurements using SSRM and Kelvin probe force microscopy (KPFM) are underway. The possibility of tuning both the electrical and optical properties of PbS thin films by doping represents a viable strategy for the development of suitable optically active materials for application in photovoltaics.