A team of researchers from Clarkson University have recently announced a significant conclusion that could have huge impacts on the futuristic growth of the nano-manufacturing industry. Their research to develop a model that will help in the process of random sequential adsorption (RSA) highlights that even a small doubt in the location of the lattice landing sites can majorly affect the density of the deposit that has been permanently formed.
The emergence of nanotechnology led to the possibility of depositing extremely small particles, and also allowed customization of the substrates or target surfaces in order to monitor the resulting structures.
The accuracy that is expected in the target surface’s pattern is discussed in this article in order to obtain high coverage and high perfection in the pattern of deposited particles. This is further elaborated by comparing RSA on three kinds of surfaces, which include a surface comprising small imprecisions in the pattern, an accurately patterned surface, and continuous (non-patterned) lattice. The team discovered that very tiny imprecisions allow the RSA to proceed under the assumption that the surface is continuous. This leads to extremely low coverage and less effective deposition process. During the RSA process, a surface that is continuous is slowly covered and a bigger fraction of the area continues to be uncovered when compared to an accurately lattice-patterned surface. Earlier, the significance of small imprecisions was not recognized when surfaces on which small imprecisions had to be placed comprised a lattice-structure or were generally continuous and flat.
This study was recently published in the Journal of Chemical Physics, from AIP Publishing.
Since 2007, Vladimir Privman at Clarkson University was majorly involved in analyzing the characteristics of such systems. However, this was the very first study to take into account the ambiguity existing in the surface lattice-site localization instead of just focusing on the uniformity of the particle’s size.
The results, primarily suggested by computer modeling, were later obtained by analytical model considerations that are unique for the research field of RSA. Pre-patterned substrates have been analyzed for applications like electronics, optics, sensors and directed crystal growth
The greatest difficulty was to understand and accept the initial numerical finding that suggested results that seemed counterintuitive. Once accepted, we could actually confirm the initial findings, as well as generalize and systematize them by analytical arguments.
The results highlights that the efforts to obtain accurate fixed positioning and object-sizing in nano-manufacturing can also become counterproductive if all these efforts are carried out as part of developing structures by RSA, under virtually irreversible conditions. Privman stated that the rate of formation and density of the desired dense structures can be efficiently enhanced by a specific relaxation degree, which permits objects to find their way into matching positions.
Implications that the researchers are planning to explore are featured in this work.
Now that we have realized that not only particle non-uniformity, but also substrate-pattern imprecision have substantial effects on the dynamics of the RSA process, we will begin studying various systems and patterning geometries, expanding beyond our original model.