Universal Current Losses in Perovskite Solar Cells Due to Mobile Ions. Issue 34 (21st July 2021)

• Record Type: Journal Article
• Authors: Thiesbrummel, Jarla; Le Corre, Vincent M.; Peña‐Camargo, Francisco; Perdigón‐Toro, Lorena; Lang, Felix; Yang, Fengjiu; Grischek, Max; Gutierrez‐Partida, Emilio; Warby, Jonathan; Farrar, Michael D.; Mahesh, Suhas; Caprioglio, Pietro; Albrecht, Steve; Neher, Dieter; Snaith, Henry J.; Stolterfoht, Martin
• Is Part Of: Advanced energy materials. Volume 11:Issue 34(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-07-21
• Subjects: current losses -- mobile ions -- non‐radiative recombination -- perovskite solar cells -- Sn perovskite -- transient photoluminescence; Energy harvesting -- Materials -- Periodicals; Energy conversion -- Materials -- Periodicals; Energy storage -- Materials -- Periodicals; Photovoltaics -- Periodicals; Fuel cells -- Periodicals; Thermoelectric materials -- Periodicals; 621.31
• DOI: 10.1002/aenm.202101447
• Languages: English
• ISSNs: 1614-6832

Abstract

Abstract: Efficient mixed metal lead‐tin halide perovskites are essential for the development of all‐perovskite tandem solar cells, however they are currently limited by significant short‐circuit current losses despite their near optimal bandgap (≈1.25 eV). Herein, the origin of these losses is investigated, using a combination of voltage dependent photoluminescence (PL) timeseries and various charge extraction measurements. It is demonstrated that the Pb/Sn‐perovskite devices suffer from a reduction in the charge extraction efficiency within the first few seconds of operation, which leads to a loss in current and lower maximum power output. In addition, the emitted PL from the device rises on the exact same timescales due to the accumulation of electronic charges in the active layer. Using transient charge extraction measurements, it is shown that these observations cannot be explained by doping‐induced electronic charges but by the movement of mobile ions toward the perovskite/transport layer interfaces, which inhibits charge extraction due to band flattening. Finally, these findings are generalized to lead‐based perovskites, showing that the loss mechanism is universal. This elucidates the negative role mobile ions play in perovskite solar cells and paves a path toward understanding and mitigating a key loss mechanism. Abstract : Current losses in perovskite solar cells (PSCs) are investigated using transient photoluminescence and charge extraction measurements. Mobile ions cause a substantial current and efficiency loss by accumulating at the perovskite/transport layer interfaces, which screens the internal electric field. This work elucidates the detrimental impact of mobile ions in PSCs and paves the path toward mitigating this key loss mechanism.