Method for detecting gas with the use of photocurrent amplification and the like and gas sensor

摘要

An indium electrode film ( 2 ) is formed closely adhering to one face of an organic semiconductor film ( 1 ) made of copper phthalocyanine while a gold electrode film ( 3 ) is formed on the other face. A voltage is applied to the organic semiconductor film ( 1 ) so that the indium electrode ( 2 ) side is biased positively. By applying a voltage so that the electrode ( 2 ) side is charged positively and irradiating with a light having a wavelength absorbable by the organic semiconductor film ( 1 ) the phenomenon of photocurrent multiplication arises at the interface of the organic semiconductor film ( 1 ) and the electrode ( 2 ). When put under an oxygen or moisture atmosphere in the above state, this gas sensor can detect oxygen or moisture depending on a change in photocurrent due to the multiplication.