Study of morphology and dye effects on the efficiency of CdS–based hybrid solar cells

In this project study, some properties of hybrid solar cells (HSCs) formed by CdS samples that were grown by the different methods (spray pyrolysis, chemical bath deposition, doctor blade and hydrothermal methods) and in different morphologies (thin film, powder and nanosphere) were investigated. Additionally, structural, morphological, optical and electrical properties of HSCs based on CdS samples whose surfaces were modified by diverse dyes (Eosin–Y, D205, N719 and N3) were studied. X–ray Diffraction (XRD) results showed the crystallization of CdS samples in the polycrystalline structure. Scanning Electron Microscopy (SEM) conclusions indicated the homogeneous coverage of P3HT on the produced CdS samples with different morphologies. Energy dispersive X–ray Spectroscopy (EDS) approved the presence of Cd and S atoms in CdS structure. It was concluded that the transmittance data of synthesized CdS specimens were quite good and hence, they can be used for the solar cell (SC) applications. It was observed that the band gaps of the prepared CdS samples were based on the method used. It was seen that the peak intensities of the absorbance of CdS-based heterostructures generally increased with the modification of CdS surface by dyes. It was observed from room temperature photoluminescence (RTPL) outputs that CdS samples produced by different routes exhibited various defects. Furthermore, it was determined that the peak intensities in the photoluminescence (PL) spectra of CdS–based heterostructures generally decreased after dye modification of CdS surface. From the electrical measurements, it was seen that CdS–based heterostructures displayed an obvious photovoltaic effect. It was observed that both CdS samples grown in the different morphology and the surface modified by diverse dyes had different power conversion efficiency (PCE) values. The highest efficiency value was appeared for CdS samples with the nanosphere morphology and modified by N719 dye as 0.881%. Thus, it can be deduced that in addition to different morphology, modification by diverse dyes also leads to an important variation on the SC efficiency.