The Fullerene C <sub> 60 </ Sub> Nano Preparation And Fluorescence Spectra Of Ultra-thin Films

Since the discovery of the C₆₀ molecule in 1985, it attracts much attention for its ideal symmetry, unique physical and chemical properties and potential applications. In 1990, Kratschmer and Huffman discovered an efficient preparation method for high pour C₆₀, the properties of C₆₀ have been extensively studied by scientists. Because of the photoelectricity characteristic of C₆₀, the study of constructing planar ordered structure become hot.The Langmuir-Blodgett (LB) technique is one of the most powerful tools to form organic ultrathin films in molecular thickness. So it is an attractive idea to form C₆₀ LB film, and to measure their PL. Usually film-forming molecules should be amphiphilic. C₆₀ molecule is not a typical amphiphilic molecule. When C₆₀ was spread on the air-water surface, the molecules of C₆₀ always aggregated. So it is very difficult to fabricate homogeneous pure C₆₀ LB film. And as a result very few works on PL of C₆₀ LB films have been carried out. The reports of the PL spectra of C₆₀ LB films are also very few.C₆₀ is of great interest because of the numerous potential applications in physics and chemistry. Among the properties of C₆₀, photoluminescence (PL) which has potential application in areas such as optics, electrics, materials science and biomedicine et al is of great importance. It is significant to investigate the emission mechanism to achieve high-quality PL of C₆₀, especially at room temperature. In the last years many studies have been focused on the optical characterization of both C₆₀ molecules and solid fullerite. In particular, PL measurements have been performed on dilute molecular solutions, films, polycrystalline powders and single crystals. The PL spectra of C₆₀ film, which have been fabricated using many methods, such as powder sublimation, epitaxial growth, cast film and so on, have been measured on varies substrate. Many groups found that the PL spectra of C₆₀ film depending on the temperature greatly and only under low temperature(≤10 K) can we get rich PL emission.In this paper, we prepara four glass of C₆₀/SA/toluene solution. Then ablate them at different time. Using TEM,we observed different structures in different solution. Comparaing the four different solution, we discover that the solution which been ablated 30minutes is adapte to preparaing C₆₀ LB film. The particle size of C₆₀ in this solution is about several nanometers.Using the four different C₆₀/SA/toluene solutions, we fabricate different C₆₀ LB films. By analyzing, the film preparaed with the solution we ablated 30minutes is better than that preparaed with other three solution. The C₆₀ cluster size is very small. The ablation time too long or too short will affect the charater of the film.Different surface topography and structure C₆₀LB films were obtained by changing the ultrasonic time of the C₆₀/SA/toluene mixed solutions. SEM images display that when the ultrasonic time is 30min, the film contain some little cluster, increasing the time to 90min, there are some bigger cluster and little rodlike structure. Along with the increasing of the ultrasonic time, some regular hollow prismatic structure appeared. The PL spectra of the film show that there are two PL spectral peaks at room temperature, as the changing of the temperature, a new peak appeared at about 768nm when decreasing the temperature to 120K.The conclusion above not only open a way for further systematic studies of C₆₀ LB film, but also provide a novel application potential of fullerne LB film in photosensitive and luminescent material.