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Title: Charge transfer of single laser crystallized intrinsic and phosphorus-doped Si-nanocrystals visualized by Kelvin probe force microscopy

Isolated intrinsic and phosphorus doped (P-doped) Si-nanocrystals (Si-NCs) on n- and p-Si substrates are fabricated by excimer laser crystallization techniques. The formation of Si-NCs is confirmed by atomic force microscopy (AFM) and conductive AFM measurements. Kelvin probe force microscopy (KPFM) is then carried out to visualize the trapped charges in a single Si-NC dot which derives from the charge transfer between Si-NCs and Si substrates due to their different Fermi levels. The laser crystallized P-doped Si-NCs have a similar Fermi level around the mid-gap to the intrinsic counterparts, which might be caused by the inactivated impurity atoms or the surface states-related Fermi level pinning. A clear rise of the Fermi level in P-doped Si-NCs is observed after a short time thermal annealing treatment, indicating the activation of dopants in Si-NCs. Moreover, the surface charge quantity can be estimated using a simple parallel plate capacitor model for a quantitative understanding of the KPFM results at the nanoscale.
Authors:
; ; ; ; ;  [1]
  1. National Laboratory of Solid State Microstructures and School of Electronic Science and Engineering, Nanjing University, Nanjing 210093 (China)
Publication Date:
OSTI Identifier:
22305767
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 13; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ANNEALING; ATOMIC FORCE MICROSCOPY; ATOMS; CAPACITORS; CRYSTALLIZATION; DOPED MATERIALS; EXCIMER LASERS; FERMI LEVEL; IMPURITIES; LASER RADIATION; NANOMATERIALS; NANOSTRUCTURES; PHOSPHORUS ADDITIONS; SILICON; SUBSTRATES; SURFACES; TRAPPING