Polymer Schottky contact on O-polar ZnO with silane coupling agent as surface protective layer

We report on a Schottky junction fabricated on O-polar ZnO surfaces with a silane-coupling agent as a protective layer, and a conducting polymer poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as a deep work function metal electrode, simply by using wet processes. The silane-coupling agent prevented the O-polar ZnO surface from an etching reaction in contact with the acidic PEDOT:PSS solution, resulting in a good rectification with a current rectification ratio of 107 at ±1V. The junction characteristics were systematically controlled in accord with the electron density in ZnO ranging from 8×1014to4×1016cm−3.