Imaging Localized Energy States in Silicon-doped InGaN Nanowires Using 4D Electron Microscopy
Burlakov, Victor M
Hedhili, Mohamed N.
Ng, Tien Khee
Ooi, Boon S.
Mohammed, Omar F.
KAUST DepartmentChemical Science Program
Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division
Electrical Engineering Program
Functional Nanomaterials Lab (FuNL)
Imaging and Characterization Core Lab
KAUST Catalysis Center (KCC)
KAUST Solar Center (KSC)
Laboratory of Nano Oxides for Sustainable Energy
Material Science and Engineering Program
Physical Science and Engineering (PSE) Division
Ultrafast Laser Spectroscopy and Four-dimensional Electron Imaging Research Group
Online Publication Date2018-01-30
Print Publication Date2018-02-09
Permanent link to this recordhttp://hdl.handle.net/10754/627010
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AbstractIntroducing dopants into InGaN NWs is known to significantly improve their device performances through a variety of mechanisms. However, to further optimize device operation under the influence of large specific surfaces, a thorough knowledge of ultrafast dynamical processes at the surface and interface of these NWs is imperative. Here, we describe the development of four-dimensional scanning ultrafast electron microscopy (4D S-UEM) as an extremely surface-sensitive method to directly visualize in space and time the enormous impact of silicon doping on the surface-carrier dynamics of InGaN NWs. Two time regime dynamics are identified for the first time in a 4D S-UEM experiment: an early time behavior (within 200 picoseconds) associated with the deferred evolution of secondary electrons due to the presence of localized trap states that decrease the electron escape rate and a longer timescale behavior (several ns) marked by accelerated charge carrier recombination. The results are further corroborated by conductivity studies carried out in dark and under illumination.
CitationBose R, Adhikari A, Burlakov VM, Liu G, Haque MA, et al. (2018) Imaging Localized Energy States in Silicon-Doped InGaN Nanowires Using 4D Electron Microscopy. ACS Energy Letters: 476–481. Available: http://dx.doi.org/10.1021/acsenergylett.7b01330.
SponsorsThe work reported here was supported by King Abdullah University of Science and Technology (KAUST).
PublisherAmerican Chemical Society (ACS)
JournalACS Energy Letters