Defect Passivation and Enhanced Hole Extraction in Inverted Perovskite Solar Cells via CeO₂@MoS₂ Interfacial...

Area of Science:

• Materials Science
• Nanotechnology
• Photovoltaics

Background:

• Nanomaterial-based hole transport layers (HTLs) are crucial for managing charge dynamics in perovskite solar cells (PSCs).
• Optimizing the interface between HTLs and perovskite layers is essential for enhancing PSC efficiency and stability.

Purpose of the Study:

• To investigate the effect of incorporating hydrothermally synthesized CeO2@MoS2 nanocomposites (CM NCs) as an interfacial buffer layer in NiOx/MeO-2PACz HTLs for PSCs.
• To enhance charge extraction, reduce recombination, and improve the power conversion efficiency (PCE) of PSCs through interface engineering.

Main Methods:

• Synthesis of CeO2@MoS2 nanocomposites via hydrothermal methods.
• Incorporation of CM NCs into NiOx/MeO-2PACz HTLs at varying concentrations (1, 2, and 4 vol%).
• Fabrication and characterization of PSC devices with modified HTLs.
• Analysis of interfacial interactions, charge transport properties, and device performance metrics (PCE, VOC).

Main Results:

• The introduction of CM NCs modulated the Ni2+/Ni3+ ratio, reduced interfacial trap density, and promoted oxygen vacancies, enhancing HTL conductivity.
• A 2 vol% CM NCs concentration yielded the highest PCE of 17.93%, surpassing the control (17.01%) and 1 vol% (17.50%) devices.
• Excessive CM NCs (4 vol%) led to performance degradation due to increased interfacial resistance and recombination.

Conclusions:

• CM NCs effectively passivate defects, reduce open-circuit voltage loss, and improve band alignment at the HTL/perovskite interface.
• Precise control over CM NCs concentration is critical for maximizing PSC performance, highlighting a robust strategy for interfacial engineering.
• This work demonstrates the potential of nanocomposite-based interfacial modification for developing high-efficiency and stable perovskite solar cells.