Highly transparent low-symmetry zinc phthalocyanine-based monolayers for NO2 gas detection

Publication date: Available online 2 October 2017
Source:Thin Solid Films
Author(s): Denis M. Krichevsky, Anton V. Zasedatelev, Alexander Yu. Tolbin, Sergey Yu. Luchkin, Alexey B. Karpo, Vitally I. Krasovskii, Larisa G. Tomilova
We demonstrate the NO2 sensing properties of transparent two-dimensional organic films based on a low-symmetry zinc phthalocyanine (Pc) complexes. The amphiphilic nature of the Pc results in oriented monolayers on substrates, which provide an excellent conformation for Zn-NO2 interactions without strong Pc intermolecular aggregation. Using the Langmuir-Blodgett technique, we form single monolayer films on glass and show their potential for NO2 gas detection. We succeed in detecting 100 ppm NO2, 20s after gas exposure. We also demonstrate total recovery of the sensing effect by simply heating up to 60°C. By exhibiting high transparency (~97%) and thermal stability, together with low costs and simplicity in scaling the technology for large-area structures, the low-symmetry zinc Pc complexes appear to be highly promising materials for gas sensing applications.