Room-temperature synthesis of ZrSnO₄ nanoparticles for electron transport layer in efficient planar hetrojunction perovskite solar cells

The interface engineering plays a key role in controlled optoelectronic properties of perovskite photovoltaic devices, and thus the electron transport layer (ETL) material with tailored optoelectronic properties remains a challenge for achieving high photovoltaic performance of planar perovskite solar cells (PSCs). Here, the fine and crystalline zirconium stanate (ZrSnO₄) nanoparticles (NPs) was synthesized at low temperature, and its optoelectronic properties are systematically investigated. Benefiting from the favorable electronic structure of ZrSnO₄ NPs for applications in ETL, efficient electron transport and extraction with suppressed charge recombination are achieved at the interface of perovskite layer. As a result, the optimized ZrSnO₄ NPs synthesized at room-temperature deliver the optimized power conversion efficiency up to 16.76 % with acceptable stability. This work opens up a new class of ternary metal oxide for the use in ETL of the planar PSCs and should pave the way toward designing new interfacial materials for practical optoelectronic devices.