In-Plane Patterning of Aggregated Nanoparticle Layers

Abstract

An in-plane patterning process of aggregated nanoparticle thin layers of different inorganic conducting and semiconducting materials produced in Langmuir−Blodgett precursors is developed using film irradiation with an electron beam. This film treatment performs cross-linking of the precursor organic molecules resulting in the insolubility of the hydrocarbon matrix in organic solvents and in the impossibility of particle aggregation in the exposed regions. After immersion of the film into the organic solvent, the exposed areas remain insulating while conducting and semiconducting layers are formed in the nontreated zones due to particle aggregation. The result of patterning is demonstrated by Brewster angle and fluorescent microscopies. The difference of electric properties of treated and nontreated regions is shown by measuring current−voltage characteristics.

Nanoparticle Organization at the Air‐Water Interface and in Langmuir‐Blodgett Films

“…An interesting application of such nanoparticle-LB film composites has been recently shown by Erokhin and co-workers [118]. They have shown that in-plane patterning of nanoparticle films may be accomplished by a simple electron irradiation process as illustrated in Fig.…”

“…Subsequently, a number of groups have investigated this approach from different angles and have reported on the in situ synthesis of nanoparticles of gold [106], CdI 2 [107], CdS [101, 108± 113], CdSe [114], PbS [115±118], TiO 2 [119], copper and copper sulfide [118,120,121] to name just some of the chemical compositions investigated. While not always leading to the formation of nanoparticles, the chemical insertion method in LB films has also been used with considerable success in realizing ultrathin films of oxides such as TiO 2 [122], Y 2 O 3 [123], ZnO [124,125] and Er 2 O 3 [126].…”

“…After formation of the nanoparticles, the film was immersed in a solvent such as chloroform and the nanoparticles aggregated in the shadow regions as shown in Fig. 12.24 c. The authors also studied the electrical conductivity of the different regions in the aggregated nanoparticle film and showed that the conductivity could vary by as much as five orders of magnitude across irradiated and non-irradiated regions of the film surface [118]. This section is concluded by mentioning a new method developed in my laboratory for realizing nanoparticles in lipid bilayer structures very similar to that obtained by chemical reaction of LB films of metal salts of fatty lipids.…”

“…All images were taken at the same magnification (reprinted with permission from [111],°1999 American Chemical Society) Fig. 12.24 Scheme of the patterning process of the aggregated layer: a irradiation of the sample by an electron beam through the mask; b formation of the particles in the sample by the chemical reaction; c aggregation of the particles by selective removal of fatty acid molecules in the non-irradiated regions (reprinted with permission from [118],°2002 American Chemical Society) used this approach to form patterned assemblies of gold [129] and CdS nanoparticles [130] and have also recently investigated the low-temperature alloying of nanoparticles produced within the thermally evaporated lipid matrices [131±134].…”

Patterning of Semiconductor Nanoparticles via Microcontact Printing

“…Thus, the functionality is naturally patterned. [5][6][7] For example, Won et al bound dendrimers on a surface, then let gold ions adsorb to the dendrimers. By UV irradiation with a photomask, patterned Au nanoparticle structures were obtained.…”