Nanowires by Step Decoration

Abstract

Recent advances in the control of thin films and surfaces have brought an intriguing question within reach: Is it possible to tailor the electronic properties of solids by controlling them layer by layer or row by row? Customized molecules are commonplace in biochemistry. Can the same idea be brought to bear on solids and electronic materials? Electronic properties of semiconductor devices have been controlled by hetero-structures, quantum wells, and super-lattices. Magnetism as a cooperative phenomenon lends itself to manipulation in small structures, where neighbor atoms can be replaced systematically by species with stronger or weaker magnetism. In fact, a class of magnetic/nonmagnetic multilayers termed spin valves has recently been introduced into commercial read heads for magnetically stored data. The optimum thickness of their active region lies in the single-digit-nanometer regime.The smallest nanostructures may be viewed as objects consisting only of interfaces with no bulk behind them. More typically, single-digit-nanometer dimensions are sufficient for realizing the benefits of structuring (e.g., operating a quantum-well device at room temperature). This regime is difficult to reach with lithography methods, particularly when macroscopic amounts are to be fabricated. Self-assembly becomes the method of choice.

Chains of gold atoms with tailored electronic states

“…Stepped Si͑111͒ templates have been prepared with high perfection by appropriate annealing sequences. [29][30][31] At low enough coverage there is only a single gold chain in the unit cell of such vicinal surfaces, while the flat Si(111)5 ϫ2-Au structure consists of two Au chains per unit cell. 32 Figure 1 shows how vicinal Si͑111͒ surfaces containing the stable ͓1 1 0͔ steps can be classified into two groups, one tilted with its normal towards the ͓1 1 2 ͔ azimuth with one broken bond at the step edge, the other towards ͓1 1 2͔ with two broken bonds.…”

Molybdenum Nanowires by Electrodeposition

“…They may form the basis of a new thin-film electronic technology, in which integrated transistor circuits are manufactured by cheap solution processing and direct printing rather than vacuum deposition and photolithographic patterning (3)(4)(5)(6) er, this requires the development of printing techniques that provide accurate definition of all components of an integrated circuit but do not compromise the ability of the organic molecules to self-assemble. Inkjet printing (IJP) has emerged as an attractive patterning technique for conjugated polymers in lightemitting diodes (7,8) and full-color highresolution displays (9).…”

On‐Chip Integration of Functional Hybrid Materials and Components in Nanophotonics and Optoelectronics

“…Decoration of step edges: At the step edges of single -crystalline surfaces, metals and other materials are deposited selectively with success [42,43] . This deposition procedure results in the generation of continuous nanowires.…”