Surface-induced p-type conductivity in ZnO nanopillars investigated by scanning probe microscopy

E. Latu-Romain (1) , P. Gilet (1) , N. Chevalier (1) , D. Mariolle (1) , François Bertin (1) , Guy Feuillet (1) , Guillaume Perillat-Merceroz (1) , Pierre Ferret (1) , Pierre Muret (2) , A. Chelnokov (1)

1 CEA-LETI - Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information
2 NEEL - SC2G - Semi-conducteurs à large bande interdite

Scanning probe microscopy (SPM) characterizations were performed on nonintentionally doped n-type ZnO nanopillars (NPs) embedded in a polymer matrix. Transport properties investigations using scanning capacitance microscopy revealed local p-type space charge regions spreading over the outer shell of the polymer-coated ZnO NP. Correlatively, different electrical behaviors were found for the core and shell parts of the NPs using scanning spreading resistance microscopy. From SPM imaging at various voltage biases and local I-V curves, an electrical transport analysis was carried out based on surface states arising from the surrounding environment. Surface barrier potential inducing ptype conductivity in polymer-coated ZnO NPs was discussed and estimated to amount to several hundreds of millielectron- volt. As a further consequence a critical diameter under which full p-type conductivity occurs in the NPs was demonstrated both theoretically and experimentally.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

E. Latu-Romain, P. Gilet, N. Chevalier, D. Mariolle, François Bertin, et al.. Surface-induced p-type conductivity in ZnO nanopillars investigated by scanning probe microscopy. Journal of Applied Physics, 2010, 107 (12), pp.124307. ⟨10.1063/1.3436596⟩. ⟨hal-00740790⟩