Synergy of 3D and 2D Perovskites for Durable, Efficient Solar Cells and Beyond

Chemical Reviews · 2023 · 213 citations

• Chemistry
• Nanotechnology
• Engineering physics

Three-dimensional (3D) organic-inorganic lead halide perovskites have emerged in the past few years as a promising material for low-cost, high-efficiency optoelectronic devices. Spurred by this recent interest, several subclasses of halide perovskites such as two-dimensional (2D) halide perovskites have begun to play a significant role in advancing the fundamental understanding of the structural, chemical, and physical properties of halide perovskites, which are technologically relevant. While the chemistry of these 2D materials is similar to that of the 3D halide perovskites, their layered structure with a hybrid organic-inorganic interface induces new emergent properties that can significantly or sometimes subtly be important. Synergistic properties can be realized in systems that combine different materials exhibiting different dimensionalities by exploiting their intrinsic compatibility. In many cases, the weaknesses of each material can be alleviated in heteroarchitectures. For example, 3D-2D halide perovskites can demonstrate novel behavior that neither material would be capable of separately. This review describes how the structural differences between 3D halide perovskites and 2D halide perovskites give rise to their disparate materials properties, discusses strategies for realizing mixed-dimensional systems of various architectures through solution-processing techniques, and presents a comprehensive outlook for the use of 3D-2D systems in solar cells. Finally, we investigate applications of 3D-2D systems beyond photovoltaics and offer our perspective on mixed-dimensional perovskite systems as semiconductor materials with unrivaled tunability, efficiency, and technologically relevant durability.

Light-activated interlayer contraction in two-dimensional perovskites for high-efficiency solar cells

Nature Nanotechnology · 2021 · 95 citations

• Materials science
• Optoelectronics
• Chemical physics

Determination of Dielectric Functions and Exciton Oscillator Strength of Two-Dimensional Hybrid Perovskites

ACS Materials Letters · 2020 · 88 citations

• Materials science
• Optoelectronics
• Condensed matter physics

Two-dimensional (2D) hybrid organic inorganic perovskite (HOIP) semiconductors have attracted widespread attention as a platform of next-generation optoelectronic devices benefiting from their naturally occurring and tunable multiple quantum-well-like (QW-like) structures, which enable a wide range of physical properties. Determining the intrinsic optical/electronic properties of 2D HOIPs is extremely important for further utility in photonic and optoelectronic devices. Here, we obtain the optical dielectric functions, complex refractive indices, and complex optical conductivities of both Ruddlesden–Popper (RP) and Dion–Jacobson (DJ) phases of 2D HOIPs, as a function of the perovskite QW thickness via spectroscopic ellipsometry over a broad energy range of 0.73–3.34 eV. We identify a series of feature peaks in the dielectric functions, and we explain the evolution of ground-state exciton peak with unit-cell thickness and changing excitonic confinement. We observe extraordinary values of optical extinction and electric loss tangents at the primary excitonic resonances and provide their detailed comparison with other known excitonic materials. Our study is expected to lay the foundation for understanding optical properties of pure-phase 2D HOIPs, which are critical and imperative for the accurate modelling of their photonic and optoelectronic devices.