H2020Индивидуална стипендия2017–2019

NanoEAscopy · Mapping Nanoscale Charge Separation at Heterojunctions with Ultrafast Electroabsorption Microscopy

„Хоризонт 2020“ — Действия „Мария Склодовска-Кюри“

Период: 2017-09-01 → 2019-08-31
Финансиране от ЕС: 183 455 €
Участници: 1
Схема: MSCA-IF-EF-ST

Линиите свързват координатора с партньорите.

Накратко на български

Разделянето на електрони и дупки при абсорбция на светлина в органични полупроводници се наблюдава чрез ултрабърза микроскопия. Разбирането на този процес помага за подобряване на ефективността на слънчевите панели и оптоелектронните устройства.

Този кратък обзор е генериран от изкуствен интелект

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

Резултати накратко

Mapping Nanoscale Charge Separation at Heterojunctions with Ultrafast Electroabsorption Microscopy

The sun is the most abundant and generously available source of renewable energy to the earth. Current consumption of solar energy is far from its enormous potential. Natural photosynthetic systems, found in plants, bacteria, and algae, use this potential with near unity photo-conversion efficiency via photoinduced charge separation (electron-hole separation). Light absorption creates electron-hole pairs which eventually undergo electron-hole separation and create free electrons and holes. Molecular level understanding of natural photosynthetic systems has paved the way for artificial photosynthetic systems. These systems are based on donor-acceptor assembly where photoinduced charge separation occurs at the donor-acceptor heterojunctions. Understanding of charge separation has gathered significant amount of interest. Despite substantial efforts being directed towards understanding the nature of charge separation, a direct visualization of charge separation at the heterojunction has never been realized. Charge-separation is the key process in photosynthesis as well as in organic semiconductor. Organic photovoltaic devices are flexible and transparent, and showing increasing efficiency. Understanding charge-separation and charge transport shall provide us with proficient schemes for molecular design and device architecture to achieve unprecedented efficiencies. This work will directly impact society since it has the potential to deliver step-increases in the efficiency of light-harvesting devices that will reduce the cost of optoelectronic devices remarkably. Overall objective of this project is to successfully optimize the ultrafast pump-probe microscope, a very fast camera, as a platform to directly image electron-hole separation at the in-plane organic heterojunctions.

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

Цел на проекта

Nanostructured electronic materials e.g. organic semiconductors (OSCs) and 2D semiconductors offer great promise for applications in optoelectronic (OE) devices, such as photovoltaics (PVs), light emitting diodes (LEDs) and photodetectors. The primary photoexcitations in both OSCs and 2D semiconductors are strongly bound excitons, quasiparticles of electrons and hole bound by the Coulomb interaction. Three aspects of these materials stand out when attempting to study photophysics of these materials. (1) Many of the crucial OE process in these systems occur at heterojunctions between p- and n-type materials, where charges recombine to form excitons and excitons dissociate to form charges. (2) The timescale for many such process is sub-ps, and charge transfer and charge separation (CS) can occur on sub-100fs timescales. (3) thin films made of these materials possess spatial inhomogeneity on µm and sub-µm length scales, due to variations in molecular packing, crystallinity and phase segregation in OSCs and due to lattice defects and variation in surface passivation and strain in 2D materials. No currently available technique has the ability to spatially correlate transient spectroscopic data with local molecular structure and composition. In order to do this, we will develop a new platform to directly image CS with sub-10fs time-resolution with sub-µm spatial resolution. Recent advances in pump-probe microscopy and ultrafast Electro-Absorption (EA) spectroscopy in the host’s group will be combined with the applicant’s expertise with optical microscopes and advanced data analysis methods to detect and quantify inhomogeneity. Novel analysis methods combined with an ultrafast EA pump-probe microscopy will allow for correlation of transient spectroscopic data with local molecular structure and composition. This will lead us to elucidate how CS is controlled by local properties such as molecular packing and crystallinity in OSCs and defect sites etc. in 2D semiconductors.

Оригинален текст от CORDIS (на английски).

Участници

THE CHANCELLOR MASTERS AND SCHOLARS OF THE UNIVERSITY OF CAMBRIDGE · CAMBRIDGEКоординаторОбединеното кралство