NTCDA organic thin-film-transistor as humidity sensor: weaknesses and strengths

1,4,5,8-Naphthalene-tetracarboxylic-dianhydride (NTCDA) organic thin-film-transistors employed as humidity sensors exhibit higher performance level compared to NTCDA chemiresitors. In particular, the transistor on-current exhibits higher values and a larger dynamic range as well as a better reversibility, compared to the response of an NTCDA resistor. On the basis of the FT-IR spectra of NTCDA humid and anhydrous thin-films, a model for the NTCDA/H2O system is proposed which eventually explains the variation of NTCDA thin-film-transistor parameters, while the device is exposed to changing water vapor atmosphere.