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 DepartmentKAUST Solar Center (KSC)
Physical Sciences and Engineering (PSE) Division
Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division
Materials Science and Engineering Program
Electrical Engineering Program
Chemical Science Program
KAUST Catalysis Center (KCC)
Imaging and Characterization Core Lab
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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