부산대학교 도서관

Air-stable organic thin-film transistor (OTFT) sensorsfabricatedusing spin-cast films of 5,9,14,18,23,27,32,36-octabutoxy-2,3-naphthalocyanine(OBNc) demonstrated improved chemical vapor sensitivity and selectivityrelative to vacuum-deposited phthalocyanine (H2Pc) OTFTs.UV–vis spectroscopy data show that annealed spin-cast OBNcfilms exhibit a red-shift in the OBNc Q-band λmaxwhich is generally diagnostic of improved π-orbital overlapin phthalocyanine ring systems. Annealed OBNc OTFTs have mobilitiesof 0.06 cm2V–1 s–1, low threshold voltages (|Vth| <1 V), and on/off ratios greater than 106. These air-stabledevice parameters are utilized for sensing modalities which enhancethe sensitivity and selectivity of OBNc OTFTs relative to H2Pc OTFTs. While both sensors exhibit mobility decreases for all analytes,only OBNc OTFTs exhibit Vthchanges forhighly polar/nonpolar analytes. The observed mobility decreases forboth sensors are consistent with electron donation trends via hydrogenbonding by basic analytes. In contrast, Vthchanges for OBNc sensors appear to correlate with the analyte’soctanol–water partition coefficient, consistent with polarmolecules stabilizing charge in the organic semiconductor film. Theanalyte induced Vthchanges for OBNc OTFTscan be employed to develop selective multiparameter sensors whichcan sense analyte stabilized fixed charge in the film. [ABSTRACT FROM AUTHOR]