Article

Interfacial engineering of potassium-assisted Fe2O3 electron extraction layer for efficient and stable perovskite solar cells

Irfan Ahmed ShaikhCentral Laboratory of The Lishui Hospital of Wenzhou Medical University, Lishui People’s Hospital, The First Affiliated Hospital of Lishui University, Lishui, Zhejiang, 323000, ChinaAkbar Ali QureshiDepartment of Mechanical Engineering, Bahauddin Zakariya University, Multan, 60000, PakistanRana Muhammad Rehan AshrafDepartment of Mechanical Engineering, Bahauddin Zakariya University, Multan, 60000, PakistanRana Muhammad ZulqarnainDepartment of Mathematics, Saveetha School of Engineering, SIMATS Thandalam, Chennai, 602105, Tamilnadu, IndiaSuhas BallalDepartment of Chemistry and Biochemistry, School of Sciences, JAIN (Deemed to be University), Bangalore, Karnataka, IndiaAman ShankhyanCentre for Research Impact & Outcome, Chitkara University Institute of Engineering and Technology, Chitkara University, Rajpura, 140401, Punjab, IndiaKarthikeyan JayabalanDepartment of CHEMISTRY, Sathyabama Institute of Science and Technology, Chennai, Tamil Nadu, IndiaXolmuratov Xolilla SariyevichUrgench State University, Khamid Olimjon 14, 220100, Urgench, UzbekistanXolmurotov FozilFaculty of Economics, Department of Economics, Mamun University, 220900, Qibla Tozabog, Khiva, UzbekistanShekhar SinghCentral Laboratory of The Lishui Hospital of Wenzhou Medical University, Lishui People’s Hospital, The First Affiliated Hospital of Lishui University, Lishui, Zhejiang, 323000, China

Results in Engineeringjournal2025en

ABI

Abstract

• Fe 2 O 3 -KCl as an electron extraction layer improved perovskite solar cell efficiency to 15.29%, a 27.6% increase over pristine Fe 2 O 3 . • Devices with Fe 2 O 3 -KCl retained 78% of their initial efficiency after 1000 hours of operation, compared to 66% for control devices. • The Fe 2 O 3 -KCl layer reduced recombination losses, leading to a higher J SC of 21.89 mA/cm 2 and a V OC of 1.03 V. • Potassium ions facilitated defect passivation and grain growth, extending carrier lifetimes and reducing trap density by 25%. Perovskite solar cells (PSCs) continue to face performance limitations arising from interfacial defects and instability. This work presents a potassium-assisted hematite (Fe 2 O 3 -KCl) electron extraction layer (EEL) as a simple yet effective interfacial engineering strategy to enhance charge extraction and device durability. The incorporation of KCl into the Fe 2 O 3 layer promotes uniform perovskite crystallization, induces a continuous columnar grain structure, and significantly reduces interfacial trap density (from 4.26 × 10 15 to 3.19 × 10 15 cm -3 ), collectively improving charge transport and suppressing non-radiative recombination. The optimized Fe 2 O 3 -KCl device achieves a power conversion efficiency (PCE) of 15.29%, showing a 27.6% enhancement over pristine Fe 2 O 3 -based cells, with strong agreement between J-V and EQE-integrated current densities. Photoluminescence, TRPL, TPV, and SCLC analyses confirm accelerated charge extraction and prolonged carrier lifetime due to effective K + /Cl - mediated defect passivation. The modified devices also exhibit improved operational stability, retaining 78% of initial PCE after 1000 hours of continuous AM1.5G illumination inside a nitrogen glovebox, compared to 66% for the control. These results demonstrate that KCl-modified Fe 2 O 3 serves as a promising, low-cost, scalable EEL for next-generation PSCs by simultaneously enhancing efficiency and long-term operational robustness.

Topics

Perovskite Materials and Applications TiO2 Photocatalysis and Solar Cells Advancements in Solid Oxide Fuel Cells

Identifiers

DOI: 10.1016/j.rineng.2025.108395

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