HEИндивидуална стипендия2023–2024

SpaceTimeFerro · Space-time visualization of photo-excited carrier dynamics in ferroelectric solar-energy converters by ultrafast electron microscopy

„Хоризонт Европа“ — Действия „Мария Склодовска-Кюри“

Период: 2023-01-01 → 2024-12-31
Финансиране от ЕС: 189 687 €
Участници: 1
Схема: HORIZON-TMA-MSCA-PF-EF

Линиите свързват координатора с партньорите.

Накратко на български

Фероелектричните материали в слънчевите клетки се изследват чрез ултрабърза електронна микроскопия, за да се види как се движат зарядните носители. Това помага за разбирането на механизмите за разделяне на зарядите, което може да подобри ефективността на превръщането на слънчевата енергия.

Този кратък обзор е генериран от изкуствен интелект

Кратко обяснение, генерирано от езиков модел по текста на CORDIS. Оригиналът е по-долу.

Резултати накратко

Space-time visualization of photo-excited carrier dynamics in ferroelectric solar-energy converters by ultrafast electron microscopy

The global demand for sustainable and efficient energy solutions has intensified due to the limitations of fossil fuels and the growing need for renewable alternatives. Current solar energy technologies, such as silicon and perovskite-based solar cells, are constrained by efficiency limits and rapid charge carrier recombination. This project addresses these challenges by exploring the potential of ferroelectric materials, which possess intrinsic electric fields that enable highly efficient photo-voltage generation beyond the conventional bandgap limits. The core objective of this research is to investigate the ultrafast photo-excited carrier dynamics in ferroelectric solar-energy converters using state-of-the-art ultrafast electron microscopy. By employing femtosecond and picometer-scale imaging, the project aims to capture the real-space dynamics of photo-generated carriers, providing fundamental insights into charge separation mechanisms and to probe the possibility of advancements in high-efficiency solar energy conversion. Ferroelectric materials have unique ability to generate an internal electric field, which helps the charge carrier separation and minimizes recombination losses. Unlike conventional semiconductor materials, where charge separation is governed by external junctions, ferroelectric solar cells exploit spontaneous polarization, making them a promising candidate for next-generation photovoltaics. However, the underlying mechanisms of charge transport and separation in these materials remain poorly understood, limiting their practical application. This project aims to unfold the unknowns by visualizing the charge carrier dynamics in real time using ultrafast electron diffraction.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз

Цел на проекта

Giant bulk photovoltaic effect in non-centrosymmetric ferroelectric materials is currently gaining tremendous research interest due to its above-bandgap photovoltage and the observed output voltage is around 3-4 orders of magnitude higher than the Si-solar cells. Hence, the ferroelectric photovoltaic response is considered the next-generation photovoltaic device. However, researchers currently lack a profound understanding of the exact mechanism of the bulk photovoltaic effect, and the proposed mechanisms are contradictory to each other. This, in turn, restricts the progress of the field towards efficient solar cells. The difficult part of finding the exact mechanism is due to ultrafast carrier dynamics and atomic relaxation times are of the order of ≈ 0.1 to 10 femtoseconds, which made it experimentally inaccessible. At present, the excellent infrastructure and facilities of my host institute dealing with the ultrafast carrier dynamics can record the meticulous dynamics in space-time resolution and hence can provide the exact mechanism towards the above bandgap photovoltage in the ferroelectric system. Therefore, through this project, we are going to investigate the origin of the anomalous bulk photovoltaic effect in perovskite ferroelectric oxides by “filming” the ultrafast photo-absorption and subsequent photo-excited carrier relaxation dynamics with femtosecond time resolution and nanometre spatial resolution using laser-driven electron microscopy. In contrast to the spectroscopic approach, ultrafast electron pulses in a femtosecond electron microscope or diffraction apparatus can provide nanometre spatial and femtosecond temporal resolutions at the same time and hence can provide a movie of evolving electromagnetic field in space and time. Based on the data generated, a comprehensive physical mechanism will be put forth, which will act as guidance for the selection and design of future ferroelectric systems for an improved photovoltaic response.

Оригинален текст от CORDIS (на английски).

Участници

UNIVERSITAT KONSTANZ · KonstanzКоординаторГермания