Directional Transformation of Heterometallic Oxo Clusters: A New Approach to Prepare Wide-Bandgap Cathode Interlayers for Perovskite Solar Cells

Typical wide-band gap cathode interlayer materials are difficulty in reducing interface recombination without limiting charge transport in perovskite solar cells (PSCs). Here, a lead-doped titanium-oxo cluster protected by S-containing ligands is introduced at the interface of perovskite and SnO2. By in situ heating, the cluster is transformed into PbSO4-PbTi3O7 heterostructure. The oxygen atoms from sulfate ion in heterostructure connect with iodine from perovskite to boost interfacial electron extraction and reduce charge recombination. While the yielded metallic interface between PbSO4 and PbTi3O7 promotes the electron transport across the interface. Finally, an efficiency as high as 24.2 % for the modified PSC is obtained. The heterostructure well-stabilize the interface of perovskite and SnO2, to greatly improve the device stability. This work provides a novel strategy to prepare wide-band gap cathode interlayer by directional transformation of heterometallic oxo clusters.

Automated summary

Researchers introduce a lead-doped titanium-oxo cluster protected by S-containing ligands at the perovskite-SnO2 interface, which is subsequently transformed into a PbSO4-PbTi3O7 heterostructure through in situ heating. The heterostructure boosts interfacial electron extraction and reduces charge recombination by connecting the oxygen atoms from sulfate ions with iodine from the perovskite, while the metallic interface between PbSO4 and PbTi3O7 promotes electron transport across the interface. This strategy achieves an efficiency as high as 24.2% for the modified perovskite solar cells and greatly improves device stability by stabilizing the interface. This work provides a novel approach for preparing wide-band gap cathode interlayers using directional transformation of heterometallic oxo clusters.