Study On Hybrid Solar Cells Based On Dendritic TiO₂/Sb₂S₃ Nanostructures

In this paper,the hierarchical TiO₂ branched nanorod array structures were prepared on FTO conduting glass with the TiO₂ seeds layer by two-step hydrothermal method.Sb₂S₃ nanoparticles were deposited on TiO₂ branched nanorod arrays by low temperature chemical bath deposition to form TiO₂/Sb₂S₃ double electron layer composite thin film electrode.Then the organic conjugated polymer P3HT was spin-coated on the TiO₂/Sb₂S₃composite film electrode,followed the hole transport layer material Spiro-OMeTAD was spin-coated,and the metal Ag as photocathode material,which was assembled into a hybrid solar cell device with a structure of FTO/TiO₂/Sb₂S₃/P3HT/Spiro-OMeTAD/Ag.The fabrication process of hybrid solar cell device was optimized by characterization and photoelectric performance testing of different thin film electrodes and cell devices.The TiO₂ branched nanorod arrays prepared under different hydrothermal reaction conditions were characterized and analyzed by SEM,TEM,XRD,transient photocurrent and UV-Vis absorption spectroscopy to determine the optimum hydrothermal reaction conditions for the TiO₂ branched nanorod arrays.The TiO₂/Sb₂S₃ composite thin film electrodes were analyzed by the same characterization method to determine the optimum conditions of chemical bath deposition.The different cell devices were investigated by means of photoluminescence,electrochemical impedance,J-V characteristic curves and open circuit voltage attenuation.The results show that the photoelectric conversion efficiency of the assembled hybrid solar cell device is 4.67%when the concentration of the added P3HT is 15 mg/mL.At this condition,the photoelectric conversion efficiency of cell devices without Sb₂S₃ sensitization is only 1.30%.Whereas the photoelectric conversion efficiency of hybrid solar cell devices assembled by replacing TiO₂ branched nanorod arrays with one-dimensional ordered TiO₂ nanorod arrays decrease from 4.67%to2.94%.Thus,the optimization of the morphology and structure of inorganic nano-semiconductor and the modification of narrow band gap semiconductor with energy level matching can effectively improve the photoelectric performance of hybrid solar cell devices.