n-ZnO/p-poly(3,4-ethylenedioxythiophene) (PEDOT) semitransparent inorganic-organic hybrid vertical heterojunction thin film diodes have been fabricated with PEDOT and ZnO thin films grown by electrodeposition and radio-frequency magnetron-sputtering respectively, onto a tin doped indium oxide coated glass substrate. The diode exhibited an optical transmission of similar to 40% to similar to 50% in the visible region between 450 and 700 nm. The current-voltage (I-V) characteristics of the heterojunction show good rectifying diode characteristics, with a ratio of forward current to the reverse current as high as 35 in the range -4 V to +4 V. The I-V characteristicwas examined in the framework of the thermionic emission model. The ideality factor and barrier height were obtained as 4.0 and 0.88 eV respectively. (c) 2012 Elsevier B.V. All rights reserved.