Abdessamad EL KANOUNY

The glass/FTO/TiO2/Sb2S3-x/P3HT/Au solar cells were investigated, with a focus on identifying the origin of performance degradation after exposure to high relative humidity and to mild heat stress. Analyzing the photovoltaic output and Deep-Level Transient Spectroscopy (DLTS) results, we probed the evolution of defect states after thermal exposure and after long-term storage of Sb2S3-x-based devices. The DLTS analysis revealed that shallow hole traps govern the stability of the Sb2S3-x cells. Significantly, it was shown that this shallow defect is not related to chlorine in the absorber, indicating an intrinsic origin. In the broader context of Sb2S3-x photovoltaics, this study underlines the paramount importance of defect engineering towards achieving more stable and efficient Sb2S3-x solar cells.

Tin selenide (SnSe) thin films were co-electrodeposited onto ITO/glass substrates from an aqueous solution containing tin(II) dichloride (SnCl2) and selenium dioxide (SeO2) as precursors, with ethylene diamine tetra-acetic acid (EDTA) as a complexing agent at 50 degrees C. The electrochemical behavior and co-deposition potentials of Sn, Se, and SnSe were analyzed using cyclic voltammetry. The influence of deposition potential on the structural, morphological, compositional, and optical properties of SnSe films was examined through X-ray diffraction, Raman spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, diffuse reflectance spectroscopy, and UV-Vis-NIR spectroscopy. The films consist of randomly arranged nanosheets and exhibit an absorption coefficient exceeding 104 cm- 1 in the visible range, and an optical band gap between 1.2 and 1.45 eV. The optimal sample showed the highest purity of the SnSe phase and the most desirable stoichiometric composition among all the prepared samples.