Air-Stable Spin-Coated Naphthalocyanine Transistors for Enhanced Chemical Vapor Detection

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• 作者：James E. Royer ; Chengyi Zhang ; Andrew C. Kummel ; William C. Trogler
• 刊名：Langmuir
• 出版年：2012
• 出版时间：April 10, 2012
• 年：2012
• 卷：28
• 期：14
• 页码：6192-6200
• 全文大小：575K
• 年卷期：v.28,no.14(April 10, 2012)
• ISSN：1520-5827

文摘

Air-stable organic thin-film transistor (OTFT) sensors fabricated using spin-cast films of 5,9,14,18,23,27,32,36-octabutoxy-2,3-naphthalocyanine (OBNc) demonstrated improved chemical vapor sensitivity and selectivity relative to vacuum-deposited phthalocyanine (H₂Pc) OTFTs. UV鈥搗is spectroscopy data show that annealed spin-cast OBNc films exhibit a red-shift in the OBNc Q-band 位_max which is generally diagnostic of improved 蟺-orbital overlap in phthalocyanine ring systems. Annealed OBNc OTFTs have mobilities of 0.06 cm² V^鈥?聽s^鈥?, low threshold voltages (|V_th| < 1 V), and on/off ratios greater than 10⁶. These air-stable device parameters are utilized for sensing modalities which enhance the sensitivity and selectivity of OBNc OTFTs relative to H₂Pc OTFTs. While both sensors exhibit mobility decreases for all analytes, only OBNc OTFTs exhibit V_th changes for highly polar/nonpolar analytes. The observed mobility decreases for both sensors are consistent with electron donation trends via hydrogen bonding by basic analytes. In contrast, V_th changes for OBNc sensors appear to correlate with the analyte鈥檚 octanol鈥搘ater partition coefficient, consistent with polar molecules stabilizing charge in the organic semiconductor film. The analyte induced V_th changes for OBNc OTFTs can be employed to develop selective multiparameter sensors which can sense analyte stabilized fixed charge in the film.