If perovskite solar cells (PSCs) with high power conversion efficiencies (PCEs) are to be commercialized, they must achieve long-term stability, which is usually assessed with accelerated degradation tests. One of the persistent obstacles for PSCs has been successfully passing the damp-heat test (85°C and 85% relative humidity), which is the standard for verifying the stability of commercial photovoltaic (PV) modules. We fabricated damp heat–stable PSCs by tailoring the dimensional fragments of two-dimensional perovskite layers formed at room temperature with oleylammonium iodide molecules; these layers passivate the perovskite surface at the electron-selective contact. The resulting inverted PSCs deliver a 24.3% PCE and retain >95% of their initial value after >1000 hours at damp-heat test conditions, thereby meeting one of the critical industrial stability standards for PV modules. Description Stabilizing inverted solar cells Although inverted (p-i-n) perovskite solar cells (PSCs) have advantages in fabrication and scaling compared with n-i-p cells, their power conversion efficiencies (PCEs ) are usually lower. Azmi et al. show that by tailoring the number of octahedral inorganic sheets in two-dimensional perovskite (2DP) passivation layers for three-dimensional perovskite active layers, PCEs of more than 24% could be achieved (see the Perspective by Luther and Schelhas). The 2DP layers formed with oleylammonium iodide molecules at the electron-selective interface passivated trap states and suppressed ion migration. These PSCs retained more than 95% of their initial efficiency after 1000 hours of damp-heat testing (85°C and 85% relative humidity), which passes a key industrial stability standard. —PDS Tailored two-dimensional perovskite passivation layers enable efficient, damp-heat stable inverted perovskite solar cells.

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Damp heat–stable perovskite solar cells with tailored-dimensionality 2D/3D heterojunctions

Perovskite-based tandem solar cells can increase the power conversion efficiency (PCE) of conventional single-junction photovoltaic devices. Here, we present monolithic perovskite/CIGSe tandem sola...

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21.6%-Efficient Monolithic Perovskite/Cu(In,Ga)Se2 Tandem Solar Cells with Thin Conformal Hole Transport Layers for Integration on Rough Bottom Cell Surfaces

Achieving a high open-circuit voltage in inverted wide-bandgap perovskite solar cells with a graded perovskite homojunction

Flexible all-perovskite tandem solar cells approaching 25% efficiency with molecule-bridged hole-selective contact

The Role of Charge Selective Contacts in Perovskite Solar Cell Stability

Current perovskite solar cell efficiency is close to silicon's record values. Yet, the roadblock for industrialization of this technology is its stability. The stability of the solar cell not only depends on the stability of the perovskite material itself but also notably on its contact layers and their interface with the perovskite, which plays a paramount role. This study rationalizes the design of new molecules to form self-assembled monolayers as a hole-selective contact. The new molecules increased the stability of the perovskite solar cells to maintain 80% of their initial PCE of 21% for 250 h at 85 °C under 1 sun illumination. The excellent charge collection properties as well as perovskite passivation effect enable the highly stable and efficient devices to demonstrate the vast potential of this new type of contact in photovoltaic application.

Robert Wenisch

Papers

Understanding the perovskite/self-assembled selective contact interface for ultra-stable and highly efficient p–i–n perovskite solar cells

Host, Suppressor, and Promoter—The Roles of Ni and Fe on Oxygen Evolution Reaction Activity and Stability of NiFe Alloy Thin Films in Alkaline Media

In vacuo XPS investigation of Cu(In,Ga)Se2 surface after RbF post-deposition treatment

Inorganic Materials as Hole Selective Contacts and Intermediate Tunnel Junction Layer for Monolithic Perovskite-CIGSe Tandem Solar Cells

Depth-resolved analysis of the effect of RbF post deposition treatment on CIGSe with two different Cu concentrations