Enhancing Organolead Halide Perovskite Solar Cells Performance Through Interfacial Engineering Using Ag-doped TiO₂ Hole Blocking Layer

Various silver-doped titanium dioxide (Ag-TiO₂) hole blocking layers are used to improve the organolead halide perovskite-structured solar cells (PSCs) performances. In this work, a series of Ag-TiO₂ compact layers with various dopant levels are successfully synthesized, and they are used to fabricate PSCs. The silver doping effects on the morphology and physical properties of Ag-TiO₂ compact layers are studied using X-ray diffractometer, UV-visible spectroscopy, contact angle meter, scanning electron microscope, atomic force microscope, and time-resolved photoluminescence spectroscopy. Furthermore, the photo-assisted Kelvin probe force microscopy is used to monitor the surface potentials. With 1.0 mol% Ag-TiO₂ PSCs, the short-circuit current density increases notably because of the lower electron–hole recombination, which increases the electron injection. After optimizing the synthesis conditions, the champion device based on 1.0 mol% Ag-TiO₂ exhibits a power conversion efficiency of 14.1% under AM 1.5 G irradiation (100 mW · cm⁻²).