Presentation Information
[23p-22C-2]Metal Halides as Surface Modification Layers for Tin-Based Perovskite Solar Cells
〇ChienYu Chen1, Fuyuki Harata1, Tomoya Nakamura1, Minh Anh Truong1, Richard Murdey1, Atsushi Wakamiya1 (1.Kyoto Univ.)
Keywords:
perovskite soalr cells,photovoltaics,interface
Recently, metal halide perovskite solar cells have attracted huge attention due to their low-cost fabrication process and increasing power conversion efficiencies (PCEs). While lead-based (Pb-based) perovskite solar cells have achieved PCEs surpassing 26%, tin-based (Sn-based) perovskite solar cells, the environmentally friendly substitutes for Pb-based perovskite solar cells, still exhibit PCEs lower than 15%. The issue with Sn perovskites is the facile oxidation of Sn2+ to Sn4+ at the surface of Sn perovskites, leading to defect-assisted carrier recombination loss and the reduced PCEs of Sn-based perovskite solar cells. To improve the performance of Sn-based perovskite solar cells, it is crucial to develop surface modification layers that can mitigate carrier recombination loss at the surface of Sn perovskites.
In this work, ultrathin metal halides were inserted between Sn-based perovskite and electron transporting layer. After introducing metal halides, the open-circuit voltage of the FA0.75MA0.25SnI3 perovskite solar cells were increased from 0.57 V to 0.70 V, with the corresponding power conversion efficiencies (PCEs) boosted from 9.7% to 12.3%. In addition, the shelf stability of the FA0.75MA0.25SnI3 solar cells was improved by the introduction of metal halides. Most importantly, we found that the concentration of Sn4+ at the surface of Sn-based perovskite was reduced from ≈ 10% to ≤ 1% after ultrathin zinc iodide (ZnI2) was vacuum-deposited on the surface of FA0.75MA0.25SnI3
In this work, ultrathin metal halides were inserted between Sn-based perovskite and electron transporting layer. After introducing metal halides, the open-circuit voltage of the FA0.75MA0.25SnI3 perovskite solar cells were increased from 0.57 V to 0.70 V, with the corresponding power conversion efficiencies (PCEs) boosted from 9.7% to 12.3%. In addition, the shelf stability of the FA0.75MA0.25SnI3 solar cells was improved by the introduction of metal halides. Most importantly, we found that the concentration of Sn4+ at the surface of Sn-based perovskite was reduced from ≈ 10% to ≤ 1% after ultrathin zinc iodide (ZnI2) was vacuum-deposited on the surface of FA0.75MA0.25SnI3