Mapping Carrier Dynamics on Material Surfaces in Space and Time using Scanning Ultrafast Electron Microscopy
KAUST DepartmentKAUST Solar Center (KSC)
Physical Sciences and Engineering (PSE) Division
Chemical Science Program
MetadataShow full item record
AbstractSelectively capturing the ultrafast dynamics of charge carriers on materials surfaces and at interfaces is crucial to the design of solar cells and optoelectronic devices. Despite extensive research efforts over the past few decades, information and understanding about surface-dynamical processes, including carrier trapping and recombination remains extremely limited. A key challenge is to selectively map such dynamic processes, a capability that is hitherto impractical by time-resolved laser techniques, which are limited by the laser’s relatively large penetration depth and consequently they record mainly bulk information. Such surface dynamics can only be mapped in real space and time by applying four-dimensional (4D) scanning ultrafast electron microscopy (S-UEM), which records snapshots of materials surfaces with nanometer spatial and sub-picosecond temporal resolutions. In this method, the secondary electron (SE) signal emitted from the sample’s surface is extremely sensitive to the surface dynamics and is detected in real time. In several unique applications, we spatially and temporally visualize the SE energy gain and loss, the charge carrier dynamics on the surface of InGaN nanowires and CdSe single crystals and its powder film. We also provide the mechanisms for the observed dynamics, which will be the foundation for future potential applications of S-UEM to a wide range of studies on material surfaces and device interfaces.
CitationMapping Carrier Dynamics on Material Surfaces in Space and Time using Scanning Ultrafast Electron Microscopy 2016 The Journal of Physical Chemistry Letters
SponsorsThe work reported here was supported by the King Abdullah University of Science and Technology.
PublisherAmerican Chemical Society (ACS)
- Enhanced Optoelectronic Performance of a Passivated Nanowire-Based Device: Key Information from Real-Space Imaging Using 4D Electron Microscopy.
- Authors: Khan JI, Adhikari A, Sun J, Priante D, Bose R, Shaheen BS, Ng TK, Zhao C, Bakr OM, Ooi BS, Mohammed OF
- Issue date: 2016 May
- Real-Space Imaging of Carrier Dynamics of Materials Surfaces by Second-Generation Four-Dimensional Scanning Ultrafast Electron Microscopy.
- Authors: Sun J, Melnikov VA, Khan JI, Mohammed OF
- Issue date: 2015 Oct 1
- Four-Dimensional Ultrafast Electron Microscopy: Insights into an Emerging Technique.
- Authors: Adhikari A, Eliason JK, Sun J, Bose R, Flannigan DJ, Mohammed OF
- Issue date: 2017 Jan 11
- Real-Space Mapping of Surface Trap States in CIGSe Nanocrystals Using 4D Electron Microscopy.
- Authors: Bose R, Bera A, Parida MR, Adhikari A, Shaheen BS, Alarousu E, Sun J, Wu T, Bakr OM, Mohammed OF
- Issue date: 2016 Jul 13
- Spatiotemporal Observation of Electron-Impact Dynamics in Photovoltaic Materials Using 4D Electron Microscopy.
- Authors: Shaheen BS, Sun J, Yang DS, Mohammed OF
- Issue date: 2017 Jun 1