ScholarWorks@성균관대학교

초록

Inverted-type perovskite solar cells (i-PSCs) have demonstrated superior power conversion efficiencies (PCEs). The bilayer of C60-SnO2 as an electron transport layer (ETL) is often used in i-PSCs. It is known, however, that the interface is quite fragile mechanically under thermal cycling. For long-term stability, the interface between the bilayer should be refined. Herein, we propose a surface treatment method on C60 to enhance the mechanical robustness between the ETL bilayer and promote efficient electron transport. The deposition of SnO2 by atomic layer deposition on ozone-treated C60 surfaces led to a reduced incubation time, as evidenced by an increase in growth per cycle (GPC) with proper ohmic contact and effective charge extraction. The treatment with O3 also significantly enhanced the interface adhesion between C60 and SnO2, which was confirmed through mechanical delamination tests and further analyzed via X-ray photoelectron spectroscopy (XPS). Consequently, the PCE of i-PSCs was 21.5% for untreated samples and 21.9% for those with the O3 treatment. The i-PSCs retained 91.9% of their initial performance under 1 sun illumination maximum power point operation for 2000 h in ambient condition. This work highlights the effectiveness of surface modification at the C60-SnO2 interfaces as ETLs in i-PSCs, leading to enhanced efficiency and stability.

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