Simultaneously enhanced efficiency and ambient stability of inorganic perovskite solar cells by employing tetramethylammonium chloride additive in CsPbI2Br

Although all-inorganic perovskites possess suitable bandgap and thermal stability for photovoltaic ap-plications,the unstable film morphologies,and poor moisture stabilities lag behind the organic-inorganic hybrid counterparts.Herein,we demonstrate that high qualityα-CsPbI_(2 ) Br films with improved phase sta-bility,high crystallinity,and pinhole-free film morphology was achieved by employing tetramethylammo-nium chloride(TMACl)as an additive.As a result,the TMACl-added CsPbI_(2) Br films exhibited high power conversion efficiency of 14.12%with an open-circuit voltage of 1.19 V,a short-circuit current density of 15.08 mA/cm^(2),and a fill factor of 0.78.More importantly,the TMACl addition imparts hydrophobicity to the film surface of CsPbI_(2) Br,which delivered excellent stability up to 30 days in the ambient condition and thermal stability at 85℃ for 156 h,respectively.Moreover,the TMACl-added device also exhibited excellent PCE of 27.16%under indoor light source(1000 lux),which presents a promising approach for designing stable but high performance all-inorganic perovskite solar cells.

Reduced interface energy loss in non-fullerene organic solar cells using room temperature-synthesized SnO2 quantum dots

We herein report the room temperature synthesis of colloidal SnO2 quantum dots and their application in non-fullerene organic solar cells as an excellent electron transport layer.The thiourea-assisted hydrolysis at room temperature affords the nanocrystalline SnO2 quantum dots with a diameter of 3-4 nm.The utilization of the SnO2 quantum dots as an electron transporting layer effectively reduces the interfacial trap density and charge recombination in the solar cell devices,leading to not only the reduced energy loss but also excellent photocurrent generation.The optimized organic solar cells employing SnO2 quantum dots with polyethylenimine ethoxylated achieves power conversion efficiencies up to 12.023%with a VOC,a JSC,and a FF of 0.89 V,18.89 mA cm^–2,and 0.72.This work suggest that the SnO2 quantum dot is a promising electron transporting material to construct efficient organic solar cells for practical applications.This work also demonstrates the key strategy for thiourea-assisted hydrolysis to synthesize fine and nanocrystalline SnO2 quantum dots.

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 suppre s sed 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.