Role of near-surface states in ohmic-Schottky conversion of Au contacts to ZnO

H. L. Mosbacker, Y. M. Strzhemechny, B. D. White, P. E. Smith, D. C. Look, D. C. Reynolds, C. W. Litton, L. J. Brillson
2005 Applied Physics Letters  
A conversion from ohmic to rectifying behavior is observed for Au contacts on atomically ordered polar ZnO surfaces following remote, room-temperature oxygen plasma treatment. This transition is accompanied by reduction of the "green" deep level cathodoluminescence emission, suppression of the hydrogen donor-bound exciton photoluminescence and a ϳ0.75 eV increase in n-type band bending observed via x-ray photoemission. These results demonstrate that the contact type conversion involves more
more » ... n involves more than one mechanism, specifically, removal of the adsorbate-induced accumulation layer plus lowered tunneling due to reduction of near-surface donor density and defect-assisted hopping transport.
doi:10.1063/1.1984089 fatcat:tpf2dpux55bkjjp7x5o47is7ma