Halide perovskite heterostructures based on 2D nanoplates building blocks for next generation optoelectronics

Project Information

HeteroPlates

Grant agreement ID: 949682

DOI

10.3030/949682

EC signature date 31 August 2020

Start date 1 March 2021

End date 28 February 2027

Funded under

• EXCELLENT SCIENCE - European Research Council (ERC)

Total cost

€ 1 872 500,00

EU contribution

€ 1 872 500,00

Coordinated by

TECHNION - ISRAEL INSTITUTE OF TECHNOLOGY
Israel

Periodic Reporting for period 3 - HeteroPlates (Halide perovskite heterostructures based on 2D nanoplates building blocks for next generation optoelectronics)

Reporting period: 2024-03-01 to 2025-08-31

Summary of the context and overall objectives of the project

HeteroPlates project addresses a critical issue in the materials science domain: the quest for an ideal material that can redefine light-matter interaction for energy conversion technologies. Despite the promising high efficiency and processing ease of metal halide perovskites, their vulnerability lies in their stability, particularly when forming interfaces with other materials. This instability is a significant barrier, hindering the realization of their full potential in photovoltaic and electro-optic applications.

Importance: In a world with an escalating demand for energy, society stands to benefit immensely from breakthroughs in energy conversion and storage. Materials that can heal themselves and maintain stability over time are not just a scientific curiosity—they represent the next leap in extending the lifespan of electronics, reducing electronic waste, and enabling more sustainable energy sources. Self-repairing capabilities within electronic materials could revolutionize industries, leading to longer-lasting devices and more resilient systems, mitigating the environmental impact of our growing energy needs.

Objectives:
To pioneer the development of next-generation heterostructures, "HeteroPlates" is designed to address the urgent need for innovative materials that can meet the global demand for energy. To transcend current technological capabilities with perovskite heterostructures, we outline the project objectives:
Exploit the high conversion efficiency and ease of processing of metal halide perovskites while overcoming their stability challenges to improve long-term device performance; this is based on observation of enhanced stability and efficiency in perovskite plates.
Develop colloidal synthesis and processes to make perovskite heterostructures. We will select interfaces significantly influencing the electronic structure, device functionality, efficiency, and stability.
Employ Bottom-up Synthesis for colloidal perovskites. We will utilize the self-organizing properties of colloidal 2D nanoplates to assemble them into controlled heterostructures, enhancing collective effects.
Develop and apply novel characterization methods to achieve unprecedented imaging resolution and insight into the heterostructures at the nanoscale. Aiming for ultra-high spatial resolution with the ability to acquire spectral information.
Translate the findings from the study of colloidal heterostructures into practical applications by creating devices that showcase new functionalities and pave the way for future technology.
Through these objectives, HeteroPlates seeks to lead a paradigm shift in material science, offering sustainable solutions to the energy sector and setting a precedent for future innovations in the field of low dimensional materials.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

At the heart of HeteroPlates is the ambition to harness these nanoplates as the bedrock for innovative heterostructures. Metal halide perovskites are semiconductors that captivated the scientific community, promising high conversion efficiency and ease of processing. Yet, their Achilles' heel lies in their stability, mainly when interfacing with other materials. Our research explores 2D perovskite interfaces, growth, and properties, paving the way for meticulously constructed perovskite heterostructures with unparalleled control over electronic architecture.
Another example demonstrates the influence of organic ligands on properties. Where similar perovskite heterostructures are used as Lego building blocks for more complex self-organized superlattices. The 2D perovskites are quantum wells and have their effective bandgap intricately defined by the thickness of the inorganic perovskite layer and the consequential quantum confinement effects. Notably, we have the capability to fine-tune the dielectric constant and modulate the spacing between monolayers through the strategic alteration of organic components. Through colloidal synthesis, we create single monolayer platelets and orchestrate these into layered 2D stacks with organic spacing molecules between them. In these stacks, the alkylamine surface ligands, varying in chain length from 4 to 18 carbons, dictate the quantum-well distances. The dynamic equilibrium that governs the free organic moieties in the solution and those on the nanocrystal surface serves as an additional knob to tune the bandgap.
This methodology of employing entropic mixing of ligands to engineer 2D excitonic interactions opens a vista of possibilities, from enhanced energy conversion to novel electronic applications, where intermixed materials can be combined to create devices with customized properties and extended operational life. This aspect of our research not only complements our existing body of work but also significantly expands the scope of our project's impact on the field of material sciences and the future of electronic device engineering.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

Sometimes, unplanned results are crucial to advancing new technologies. This was precisely the story behind the discovery of self-healing, lead-free perovskites. Our team, while studying the structure and interfaces of perovskite nanocrystals, stumbled upon the conditions that allow self-healing capabilities of double perovskite nanocrystals, a revelation that could spell a new era for photovoltaic and electro-optic applications. By meticulously observing the dynamics of crystal voids, we have made the connection between the surface protection layer of the nanocrystals and the self-repairing process. The absence of organic ligands triggers a transformative self-healing mechanism, allowing diffusion of voids to the surface and enabling further crystallization of the material to a perfect crystal. This Hints at the immense potential of surface engineering for enhancing material efficiency and stability. These strides are not merely academic pursuits; they are stepping stones towards a future of a new concept of self-repairing electronics, where the longevity of devices is no longer a constraint but a dynamic feature.