Interface Engineering of 2D/3D Perovskite Heterojunction Improves Photovoltaic Efficiency and Stability

Abstract

The instability of 3D perovskite and the low power conversion efficiency (PCE) of 2D perovskite limit the development of perovskite solar cells (PSCs). Using 2D perovskite to passivate 3D perovskite thin films by heterojunction engineering has become an effective strategy to develop stable and efficient PSCs. Therefore, it is important to find suitable 2D perovskite passivation materials. Herein, a 2D/3D heterojunction perovskite is formed in situ by introducing a long‐chain alkyl phenylbutylammonium (PBA+) cation. The 2D perovskite has the property of n = 2, which passivates the surface defects of the 3D perovskite, resulting in enhanced photoluminescence intensity and prolonged carrier lifetime. Moreover, the 2D layer changes the interface contact and energy‐level arrangement, making it a more n‐type semiconductor, which facilitates the electron transfer between perovskites and electron transport. This strategy significantly improves the open circuit voltage (Voc) and fill factor (FF) of the devices without sacrificing current, and the PCE is improved from 19.22% to 21.76%. The hydrophobic PBA+‐based 2D layer also improves the humidity stability of the films and enhances the working stability of the device. The PCE of the champion heterojunction perovskite device remains 87% of its initial value after illumination for 1000 h. The results show that heterojunction engineering plays an important role in the preparation of efficient and stable PSCs.

Perovskite Passivation with a Bifunctional Molecule 1,2‐Benzisothiazolin‐3‐One for Efficient and Stable Planar Solar Cells

“…[18] In Figure 2e, a new π-π peak appears at 291.2 eV from the C 1s level, which is the characteristic peak of the benzene ring in the BIT molecule, confirming the existence of BIT in the film. [19] And the XPS peak from the Pb 4f level shift to higher binding energy in the CsFAMA: BIT film, manifesting that there is an interaction between the uncoordinated Pb 2þ and the BIT in the doped film (shown in Figure 2f ). [20] As it was revealed in the previous calculation, the lone pair electrons of both the S atom and O atom form a strong bond with the Pb 2þ on the perovskite grain surface, resulting in lower formation energy and a more stable structure.…”

Efficient and Stable FA‐Rich Perovskite Photovoltaics: From Material Properties to Device Optimization

“…The 2D/3D perovskite showed an ultralong charge-carriers lifetime of more than 1.5 ms, the finished device obtained a recording efficiency of 22.7% and outstanding operation stability and thermodynamic stability. Recently, Ji et al [139] prepared a 2D/3D heterostructure in-site by depositing long-chain alkyl ammonium salt PBAI on the surface of 3D perovskite. The 2D perovskite could passivate surficial defects, prolonged carrier lifetime, and adjust energy-level arrangement, boosting the PCE to 21.76% from 19.22%.…”

Construction of Bi2S3/TiO2/MoS2 S‐Scheme Heterostructure with a Switchable Charge Migration Pathway for Selective CO2 Reduction

“…[ 4–6 ] Therefore, an excellent photocatalyst should feature broad light absorption, proper heterojunction interfacial contact, a low electron/hole recombination rate, high charge transport, an appropriate redox potential, and CO 2 product selectivity. [ 7–11 ] Particularly, for an effective reduction reaction, the heterostructure should have a proper conduction band minimum (CBM) potential, which should be higher than the potential of the selective reduction product.…”

“…product selectivity. [7][8][9][10][11] Particularly, for an effective reduction reaction, the heterostructure should have a proper conduction band minimum (CBM) potential, which should be higher than the potential of the selective reduction product.…”

“…[13,[22][23][24][25][26][27][28][29] Multidimensional structure architecture results in a higher surface area and optimal interfacial interaction of semiconducting photocatalysts, contributing to higher photocatalytic efficiency by accelerating electron and hole transportation, and impeding their recombination. [11,24,[30][31][32] The conversion of CO 2 to a specific product is highly desirable for energy conversion. However, the CO 2 conversion product depends primarily on the CB redox potential of the accumulated electrons.…”