Particle atomic layer deposition

Abstract

The functionalization of fine primary particles by atomic layer deposition (particle ALD) provides for nearly perfect nanothick films to be deposited conformally on both external and internal particle surfaces, including nanoparticle surfaces. Film thickness is easily controlled from several angstroms to nanometers by the number of self-limiting surface reactions that are carried out sequentially. Films can be continuous or semi-continuous. This review starts with a short early history of particle ALD. The discussion includes agitated reactor processing, both atomic and molecular layer deposition (MLD), coating of both inorganic and polymer particles, nanoparticles, and nanotubes. A number of applications are presented, and a path forward, including likely near-term commercial products, is given.

Using Hot Electrons and Hot Holes for Simultaneous Cocatalyst Deposition on Plasmonic Nanostructures

“…Trimethylaluminum oxide (ALD precursor for Al 2 O 3 deposition) does not bind well on the Au surface, so probably a deposition of 1–5 nm of Al 2 O 3 results in some pinholes on the Au nanoislands that penetrate through the entire layer. 64 The addition of thicker layers of ALD Al 2 O 3 before current is eliminated has also been observed in halide perovskite solar cells recently. 65 The dependence of the photocurrent on the thickness of the insulating layer provides additional verification that the oxidation of Mn 2+ to MnO x is the result of a hot hole rather than a purely thermal or chemical reaction mechanism.…”

Design of PtZn nanoalloy catalysts for propane dehydrogenation through interface tailoring via atomic layer deposition

“…Generally, the independence of the loading from temperature and amount of dosed precursor is taken as proof that the conditions for ALD are fulfilled and the process operates within the ALD window. [53][54][55][56] Furthermore, Libera et al, 57 reported that the deposition of Zn via ALD on SiO 2 particles at temperatures above 150 °C yields metallic Zn and ZnO simultaneously. The presence of metallic Zn is reported as an indication of a chemical vapour deposition (CVD) process occurring in parallel.…”

Surface functionalization on nanoparticles via atomic layer deposition

“…The complete encapsulation of particles is a major category that utilizes ALD advantages of conformal and uniform growth to deposit pinhole-free films of critical thickness at nanometer scale [30]. The conformal coating is mainly used to protect the coated materials and increase stability while keeping the original properties of the primary particles.…”