Despite the rapid efficiency increase,tin halide perovskite solar cells are significantly behind their lead-based counterpart,with the highest reported efficiency of 15.38%.The main reason for this large difference is...Despite the rapid efficiency increase,tin halide perovskite solar cells are significantly behind their lead-based counterpart,with the highest reported efficiency of 15.38%.The main reason for this large difference is attributed to the instability of Sn^(2+),which easily oxidizes to Sn^(4+),creating Sn vacancies and increasing the open-circuit voltage loss.In this work,we implemented tin thiocyanate(Sn(SCN)_(2))as an additive for passivating the bulk defects of a germanium-doped tin halide perovskite film.Adding Sn^(2+)and SCN-ions reduces the Sn and iodine vacancies,limiting non-radiative recombination and favoring longer charge-carrier dynamics.Moreover,the addition of Sn(SCN)_(2) induces a higher film crystallinity and preferential orientation of the(l00)planes parallel to the substrate.The passivated devices showed improved photovoltaic parameters with the best open-circuit voltage of 0.716 V and the best efficiency of 12.22%,compared to 0.647 V and 10.2%for the reference device.In addition,the passivated solar cell retains 88.7%of its initial efficiency after 80 min of illumination under 100 mW cm^(-2) and is substantially better than the control device,which reaches 82.6%of its initial power conversion efficiency only after 30 min.This work demonstrates the passivation potential of tin-based additives,which combined with different counterions give a relatively large space of choices for passivation of Sn-based perovskites.展开更多
基金support from the Focus Group‘Next Generation Organic Photovoltaics’participating with the Dutch Institute for Fundamental Energy Research(DIFFER)(FOM130)Advanced Materials research program of the Zernike National Research Centre under the Bonus Incentive Scheme(BIS)of the Dutch Ministry for Education,Culture and Science.
文摘Despite the rapid efficiency increase,tin halide perovskite solar cells are significantly behind their lead-based counterpart,with the highest reported efficiency of 15.38%.The main reason for this large difference is attributed to the instability of Sn^(2+),which easily oxidizes to Sn^(4+),creating Sn vacancies and increasing the open-circuit voltage loss.In this work,we implemented tin thiocyanate(Sn(SCN)_(2))as an additive for passivating the bulk defects of a germanium-doped tin halide perovskite film.Adding Sn^(2+)and SCN-ions reduces the Sn and iodine vacancies,limiting non-radiative recombination and favoring longer charge-carrier dynamics.Moreover,the addition of Sn(SCN)_(2) induces a higher film crystallinity and preferential orientation of the(l00)planes parallel to the substrate.The passivated devices showed improved photovoltaic parameters with the best open-circuit voltage of 0.716 V and the best efficiency of 12.22%,compared to 0.647 V and 10.2%for the reference device.In addition,the passivated solar cell retains 88.7%of its initial efficiency after 80 min of illumination under 100 mW cm^(-2) and is substantially better than the control device,which reaches 82.6%of its initial power conversion efficiency only after 30 min.This work demonstrates the passivation potential of tin-based additives,which combined with different counterions give a relatively large space of choices for passivation of Sn-based perovskites.
