Conductivity of quantum dot arrays

Abstract

Arrays of quantum dots (QDs), i.e., semiconducting nanoparticles with typical sizes of 3–10 nm, have become more than merely an object of scientific research; they are now used in electronic devices. They are appealing mainly due to their optical properties, which depend on the QD size. Here, we consider the electronic properties of such arrays. These properties typically inherit the properties of bulk semiconductors, but in some cases can be substantially different due to the discreteness of sizes and a particular type of disorder in the array: the difference in size and spacing among QDs, as well as the number of donors. Notably, in such arrays, the metal–dielectric transition occurs at a much higher concentration of donors than in the bulk material. The nature of hopping conductivity in the dielectric phase strongly depends on the disorder type, quantum confinement effects, the Coulomb blockade, and the overlap integral of QDs.

Thermodynamically Stable Colloidal Solids: Interfacial Thermodynamics from the Particle Size Distribution

“…The optimization of synthetic processes has primarily proceeded along the lines of controlling the kinetics of the nucleation and growth of particles, − and equilibrium thermodynamics is generally invoked only in providing the driving force for the precipitation of the solid or in stabilizing specific crystalline surfaces. − Underlying these priorities is the unspoken assumption that colloidal nanoparticles fall into the class of lyophobic colloids; that is, collections of nanoparticles are inherently unstable and inevitably will aggregate or coarsen to minimize their total surface or interfacial area if they are allowed to exchange mass or contact each other. Such an outcome is undesirable both for displacing the distribution of particle sizes from its chosen mean and for broadening that distribution, the latter of which especially conflicts with demands − on its narrowness (monodispersity) for applications of colloidal particle assemblies.…”