Suppressing Nonradiative Losses in Wide-Band-Gap Perovskites Affords Efficient and Printable All-Perovskite Tandem Solar Cells with a Metal-Free Charge Recombination Layer

Abstract

Although the efficiencies of all-perovskite tandem solar cells have surpassed 26%, further advancement of device performance is constrained by the large photovoltage deficit in wide-band-gap perovskite subcells. Meanwhile, state-of-the-art charge recombination layers incorporate an additional thin metal film (Au or Ag), which not only complexes device fabrication but induces parasitic optical losses. Here, we first fabricate efficient wide-band-gap perovskite solar cells (PSCs) with by suppressing nonradiative losses both in bulk material and at interface. The prepared PSCs with a band gap of 1.71 eV yield an impressive open-circuit voltage (V OC) of 1.27 V, giving a small V OC deficit of 0.44 V and an efficiency of 20.8%. We then fabricate monolithic all-printed perovskite tandem devices by constructing a metal-free recombination layer, which yields an efficiency of 23.65% and a high V OC of 2.05 V. This work offers a simple yet effective charge recombination architecture for advancing the performance of all-perovskite tandem devices.

Low‐Dimensional 2‐thiopheneethylammonium Lead Halide Capping Layer Enables Efficient Single‐Junction Methylamine‐Free Wide‐Bandgap and Tandem Perovskite Solar Cells

“…[ 3 ] To further improve the PCE, multi‐junction solar cells hold the potential to raise the PCE beyond the S–Q limits. Specifically, perovskite‐based tandem solar cells (TSCs) composed of a top wide‐bandgap (WBG) perovskite subcell and a bottom narrow‐bandgap (NBG) subcell have been considered as promising alternatives, such as wide‐bandgap perovskite/narrow‐bandgap perovskite, [ 4–9 ] perovskite/crystalline silicon, [ 10–14 ] perovskite/copper indium gallium diselenide, [ 15–18 ] and perovskite/organic tandem cells. [ 19–21 ] Among them, WBG PSCs are a critical component in achieving highly efficient perovskite‐based TSCs.…”

Bottom-up modification boosts the performance of narrow-bandgap lead–tin perovskite single-junction and tandem solar cells

“…4 Specifically, narrowbandgap Pb-Sn perovskite solar cells are suitable as bottom subcells for tandem solar cells, which are promising for achieving high efficiencies that exceed the single-junction Shockley-Queisser limits. [5][6][7][8][9][10] Typically, all-perovskite tandem solar cells consist of widebandgap (B1.77 eV) perovskite subcells with mixed halides of Br and I for absorbing short-wavelength light and narrowbandgap Pb-Sn perovskite subcells for harvesting longwavelength light. Consequently, mixed Pb-Sn perovskite solar cells are a fundamental element for efficient all-perovskite tandem solar cells.…”

“…4 Specifically, narrow-bandgap Pb–Sn perovskite solar cells are suitable as bottom subcells for tandem solar cells, which are promising for achieving high efficiencies that exceed the single-junction Shockley–Queisser limits. 5–10…”

Intermediate Phase Formation and its Manipulation for Vacuum‐Assisted Blade‐Coated Wide‐Bandgap Perovskite

“…[ 28,31 ] Impressively, Mai's group reported the highest PCE of 23.65% recently based on the vacuum‐assisted blade‐coated all‐perovskite tandem solar cells, further rendering its huge potential in high‐efficiency perovskite tandem solar cells. [ 30 ]…”