Films, epitaxial inorganic

LE MOIGNE J., THIERRY A., CHOLLET P.A., KAJZAR F. and MESSIER J., (1988a), "Thin Film Epitaxy of Diacetylenes on Inorganic or Organic Substrates Structure and Nonlinear Properties of Polymerized Films", SPIE, Vol. 971. Nonlinear Optical Properties of Organic Materials, 173-... 

The most flexible methods, which can be applied in principle to nearly all molecules and which provide the most important techniques for the preparation of organic molecular films, are vacuum evaporation and molecular-beam epitaxy (cf [14]). In both methods, the substance required is evaporated or sublimed and captured on a substrate which is cooled as necessary. In molecular-beam epitaxy, the substrate must be an (inorganic) single crystal. The nature of the substrate s surface, its temperature and the velocity of evaporation or sublimation, adjustable... 

Atomic layer deposition (ALD), originally termed atomic layer epitaxy, was pioneered and patented by T. Suntola and coworkers for growing ZnS (Suntola and Antson, 1977). Initial motivation for the development of ALD came from thin film electroluminescent displays. After extensive research advances in the past 40 years, ALD, which allows deposition at the atomic or molecular level, can be used for a variety of thin films such as metal oxides and nitrides, polymers, and inorganic—organic... 

Recently, many scientists and engineers have looked for methods to control the sizes of QDs and make possible the formation of ordered lateral two-dimensional superlattices or vertical superlattices for heterojunction thin films. One approach is the top-down method, molecular beam epitaxy nanolithographic technology, which has been developed with the development of microelectronics and processing techniques for traditional inorganic semiconductors. This technique of nanoscale manipulation can reach only the upper limits of sizes defined by nanostructure physics, and has successfully manipulated artificial atoms and molecules [10-12). Bottom-up method is based on molecular and supramolecular assembly techniques that have been proposed by chemists in recent years. With this method, it is possible to prepare monodispersed defect-free nanocrystal QDs 1-10 nm in size and to control easily QDs coupling to form nanocrystal molecules, even quantum dot superlattices in two or three dimensions. 

Monolayers provide a two-dimensional matrix to mimic the biomineralization process for growing inorganic thin films or crystals [187]. The main concept behind this approach is the view pioneered by Lowenstam [188] that protein layers like, for example, the b-sheets in nacre, have an epitaxial arrangement of functional groups to specific crystal faces. The influence of surfactant headgroups with different functionalities on the crystallization of CaCOs [189-191] and BaS04 [192-194], under control of monolayers which are formed from saturated long alkyl chain carboxylates, sulfates, amines, and alcohols, has been studied. 

---