Double-Sided Surface Passivation of 3D Perovskite Film for High-Efficiency Mixed-Dimensional Perovskite Solar Cells

Date

2019

Authors

Mahmud, Md Arafat
Duong, The
Yin, Yanting
Pham, Huyen
Walter, Daniel
Peng, Jun
Wu, Yiliang
Li, Li
Shen, Heping
Wu, Nandi

Journal Title

Journal ISSN

Volume Title

Publisher

Wiley-VCH Verlag GMBH

Abstract

Defect-mediated carrier recombination at the interfaces between perovskite and neighboring charge transport layers limits the efficiency of most state-of-the-art perovskite solar cells. Passivation of interfacial defects is thus essential for attaining cell efficiencies close to the theoretical limit. In this work, a novel double-sided passivation of 3D perovskite films is demonstrated with thin surface layers of bulky organic cation-based halide compound forming 2D layered perovskite. Highly efficient (22.77%) mixed-dimensional perovskite devices with a remarkable open-circuit voltage of 1.2 V are reported for a perovskite film having an optical bandgap of ≈1.6 eV. Using a combination of experimental and numerical analyses, it is shown that the double-sided surface layers provide effective defect passivation at both the electron and hole transport layer interfaces, suppressing surface recombination on both sides of the active layer. Despite the semi-insulating nature of the passivation layers, an increase in the fill factor of optimized cells is observed. The efficient carrier extraction is explained by incomplete surface coverage of the 2D perovskite layer, allowing charge transport through localized unpassivated regions, similar to tunnel-oxide passivation layers used in silicon photovol-taics. Optimization of the defect passivation properties of these films has the potential to further increase cell efficiencies.

Description

Keywords

mixed-dimensional perovskite, passivation, solar cells, surface bandgap widening

Citation

Source

Advanced Functional Materials

Type

Journal article

Book Title

Entity type

Access Statement

License Rights

DOI

10.1002/adfm.201907962

Restricted until

2099-12-31