Doped semiconductor nanocrystal junctions studied by Kelvin probe and non-contact atomic force microscopy - Archive ouverte HAL Accéder directement au contenu
Communication Dans Un Congrès Année : 2013

Doped semiconductor nanocrystal junctions studied by Kelvin probe and non-contact atomic force microscopy

Résumé

Semiconductor junctions are the basis of electronic and photovoltaic devices. Here, we investigate junctions formed from highly doped (ND~10^20-10^21 cm-3) hydrogen-passivated silicon nanocrystals (NCs) in the 2-50nm size range, using non-contact atomic force microscopy coupled to Kelvin probe force microscopy experiments with single charge sensitivity, in ultra-high vacuum. We first describe the energy equilibrium associated with the charge transfer, as measured from Kelvin probe microscopy measurement. It reveals the NC quantum confinement (blue-shift of the silicon NC conduction band edges as a function of the nanocrystal size, typically up to the eV range), in good quantitative agreement with tight-binding calculations for hydrogen-passivated silicon nanocrystals. We also show that the charge transfer from doped NCs towards a two-dimensional layer experimentally follows a simple phenomenological law, corresponding to formation of an interface dipole linearly increasing with the NC diameter. These feature lead to analytically predictable junction properties down to quantum size regimes: NC depletion width independent of the NC size and varying as ND-1/3, and depleted charge linearly increasing with the NC diameter and varying as ND1/3. This analytical model establishes a "nanocrystal counterpart" of conventional semiconductor planar junctions, valid in regimes of strong electrostatic and quantum confinements.
Fichier non déposé

Dates et versions

hal-00944018 , version 1 (11-02-2014)

Identifiants

  • HAL Id : hal-00944018 , version 1

Citer

Lukasz Borowik, Thuat Nguyen-Tran, D. Deresmes, Heinrich Diesinger, Pere Roca I Cabarrocas, et al.. Doped semiconductor nanocrystal junctions studied by Kelvin probe and non-contact atomic force microscopy. Materials Research Society Fall Meeting, MRS Fall 2013, Symposium LL : Advances in Scanning Probe Microscopy, 2013, Boston, MA, United States. ⟨hal-00944018⟩
110 Consultations
0 Téléchargements

Partager

Gmail Facebook X LinkedIn More