Fabrication of 3D Thin Films by Spray Pyrolysis Method from Metal Phthalocyanines

One of the emerging research areas aimed at improving the physicochemical properties of metallophthalocyanines is "nanostructuring". The spectrum of nanomaterials used in sensors is wide; the analysis of recent publications has made possible to identify various nanomaterials that have found applications as chemical sensors [1-9]. These include the following groups of nanomaterials: 1) nanoparticles, nanoclusters, nanocrystals and quantum dots, used mainly in optical, including biochemical immunosensors, less often in electrochemical sensors; 2) nanotubes, nanorods, nanowires, nanowires, used primarily in electrical (field effect transistor) and electrochemical sensors, less often in optical (biochemical) and piezosensors; 3) sensors based on the use of nanoscale organized film structures (Langmuir-Blodgett films and selfassembled mono- and multilayers), used mainly in optical, surface-acoustic and piezo-quartz (volume-acoustic) sensors. All kinds of nanoscale particles can be embedded in various organic or inorganic matrices (monolayers or films). Nanosensors based on such composite materials are used mainly for the detection of gases, although there are examples of their use in the analysis of liquid media. Carbon nanotubes have a number of unique properties that make their use promising in chemical sensors [10,11], and a wide range of electrical properties. Most of the tubes are semiconductors, but there are excellent conductors (in particular, better than silver) and even insulators. The conductivity of a nanotube depends on its geometric structure.

Phthalocyanine-based macrocycle systems (Pc) and their metal complexes (MPc) are promising candidates for classic applications, such as, for example, pigments [12], solar [13] and fuel cells [14], catalysts [15], semiconductors [16], gas sensors [17], corrosion inhibitors [18], electronic [19] and optical [20] devices, liquid crystalline materials [21], but also for design of nanomaterials [22,23]. Their surface chemistry [23] is a relatively young and growing field of research, caused by the tremendous versatility of these molecules and their metal complexes. Phthalocyanine complexes are formed with most metallic elements of the periodic system and, depending on the type of metal center, enormous variations in reactivity, electronic and magnetic properties and biological functionality can be found. Phthalocyanines share the conjugated πextended system with porphyrins and, therefore, also share the ability of a strong absorption of light in the visible range. These macrocycles are thermally very stable and up to 500-800 K, so their thin films can be easily prepared by organic molecular beam epitaxy (OMBE) in vacuum [24]. Exploiting the intrinsic electronic, optic and spintronic properties of novel low-dimensional molecular materials, it is required that the electronic coupling with the supporting substrate is kept as low as possible.