Tin chloride perovskite-sensitized core/shell photoanode solar cell with spiro-MeOTAD hole transport material for enhanced solar light harvesting

An attempt has been made to fabricate methyl ammonium tin chloride (CH3NH3SnCl3) perovskite-sensitized TiO2 nanostructure photoanode solar cell with hole transport material (HTM) spiro-MeOTAD and graphite-coated counter electrode (CE). The TiO2 nanoparticles (TNPs), TiO2 nanoleaves (TNLs), and TNLs with MgO core/shell photoanodes were prepared to fabricate perovskite-sensitized solar cells (PSSCs). The prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The photovoltaic characteristics of the PSSCs, photocurrent density (J (sc)), open-circuit voltage (V (oc)), fill factor (FF), and power conversion efficiency (PCE) were determined under illumination of AM 1.5 G. Electrochemical impedance spectroscopy (EIS) analysis was carried out to study the charge transport and lifetime of charge carriers at the photoanode-sensitizer-electrolyte interface of the PSSCs. The PSSC made with CH3NH3SnCl3 perovskite-sensitized TNL-MgO core/shell photoanode and spiro-MeOTAD HTM shows an impressive photovoltaic performance, with J (sc) = 17.24 mA/cm(2), V (oc) = 800 mV, FF = 73 %, and PCE = 9.98 % under 100 mW/cm(2) light intensity. The advent of such simple solution-processed mesoscopic heterojunction solar cells paves the way to realize low-cost and high-efficiency solar cells. By the aid of electrochemical impedance spectroscopy, it is revealed that the core/shell structure can increase an interfacial resistance of the photoanode-CH3NH3SnCl3 interface and retard an electron recombination process in the photoanode-sensitizer-HTM interface.