The Investigation of the Influence of a Cu<sub>2</sub>O Buffer Layer on Hole Transport Layers in MAPbI<sub>3</sub>-Based Perovskite Solar Cells

The passivation engineering of the hole transport layer in perovskite solar cells (PSCs) has significantly decreased carrier accumulation and open circuit voltage (<i>V<sub>oc</sub></i>) loss, as well as energy band mismatching, thus achieving the goal of high-power conversio...

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Bibliographic Details
Main Authors: Chunxiang Lin, Guilin Liu, Xi Xi, Lan Wang, Qiqi Wang, Qiyan Sun, Mingxi Li, Bingjie Zhu, David Perez de Lara, Huachao Zai
Format: Article
Language:English
Published: MDPI AG 2022-11-01
Series:Materials
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Online Access:https://www.mdpi.com/1996-1944/15/22/8142
Description
Summary:The passivation engineering of the hole transport layer in perovskite solar cells (PSCs) has significantly decreased carrier accumulation and open circuit voltage (<i>V<sub>oc</sub></i>) loss, as well as energy band mismatching, thus achieving the goal of high-power conversion efficiency. However, most devices incorporating organic/inorganic buffer layers suffer from poor stability and low efficiency. In this article, we have proposed an inorganic buffer layer of Cu<sub>2</sub>O, which has achieved high efficiency on lower work function metals and various frequently used hole transport layers (HTLs). Once the Cu<sub>2</sub>O buffer layer was applied to modify the Cu/PTAA interface, the device exhibited a high <i>V<sub>oc</sub></i> of 1.20 V, a high <i>FF</i> of 75.92%, and an enhanced <i>PCE</i> of 22.49% versus a <i>V<sub>oc</sub></i> of 1.12 V, <i>FF</i> of 69.16%, and PCE of 18.99% from the (PTAA/Cu) n-i-p structure. Our simulation showed that the application of a Cu<sub>2</sub>O buffer layer improved the interfacial contact and energy alignment, promoting the carrier transportation and reducing the charge accumulation. Furthermore, we optimized the combinations of the thicknesses of the Cu<sub>2</sub>O, the absorber layer, and PTAA to obtain the best performance for Cu-based perovskite solar cells. Eventually, we explored the effect of the defect density between the HTL/absorber interface and the absorber/ETL interface on the device and recommended the appropriate reference defect density for experimental research. This work provides guidance for improving the experimental efficiency and reducing the cost of perovskite solar cells.
ISSN:1996-1944