Real-space Mapping of Surface Trap States in CIGSe Nanocrystals using 4D Electron Microscopy
Parida, Manas R.
Shaheen, Basamat S.
Mohammed, Omar F.
KAUST DepartmentChemical Science Program
KAUST Catalysis Center (KCC)
KAUST Solar Center (KSC)
Materials Science and Engineering Program
Physical Sciences and Engineering (PSE) Division
Online Publication Date2016-05-31
Print Publication Date2016-07-13
Permanent link to this recordhttp://hdl.handle.net/10754/611354
MetadataShow full item record
AbstractSurface trap states in semiconductor copper indium gallium selenide nanocrystals (NCs) which serve as undesirable channels for non-radiative carrier recombination, remain a great challenge impeding the development of solar and optoelectronics devices based on these NCs. In order to design efficient passivation techniques to minimize these trap states, a precise knowledge about the charge carrier dynamics on the NCs surface is essential. However, selective mapping of surface traps requires capabilities beyond the reach of conventional laser spectroscopy and static electron microscopy; it can only be accessed by using a one-of-a-kind, second-generation four-dimensional scanning ultrafast electron microscope (4D S-UEM) with sub-picosecond temporal and nanometer spatial resolutions. Here, we precisely map the surface charge carrier dynamics of copper indium gallium selenide NCs before and after surface passivation in real space and time using S-UEM. The time-resolved snapshots clearly demonstrate that the density of the trap states is significantly reduced after zinc sulfide (ZnS) shelling. Furthermore, removal of trap states and elongation of carrier lifetime are confirmed by the increased photocurrent of the self-biased photodetector fabricated using the shelled NCs.
CitationReal-space Mapping of Surface Trap States in CIGSe Nanocrystals using 4D Electron Microscopy 2016 Nano Letters
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
- Mapping Carrier Dynamics on Material Surfaces in Space and Time using Scanning Ultrafast Electron Microscopy.
- Authors: Sun J, Adhikari A, Shaheen BS, Yang H, Mohammed OF
- Issue date: 2016 Mar 17
- 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 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
- Visualization of Charge Carrier Trapping in Silicon at the Atomic Surface Level Using Four-Dimensional Electron Imaging.
- Authors: Shaheen BS, El-Zohry AM, Yin J, De Bastiani M, De Wolf S, Bakr OM, Mohammed OF
- Issue date: 2019 Apr 18