Electrical Transport in Semiconductor Nanoparticle Arrays: Conductivity, Sensing and Modeling

Abstract

AbstractElectrical properties of nanoparticle ensembles are dominated by interparticle transport processes, mainly due to particle–particle and particle-contact interactions. This makes their electrical properties dependent on the network properties such as porosity and particle size and is a main prerequisite for solid- state gas sensors, as the surrounding gas atmosphere influences the depletion layer surrounding each particle. Different kinds of nanoparticle arrays such as pressed pellets, printed layer, and thin films prepared by molecular beam-assisted deposition are characterized with respect to their electrical transport properties. Experimental results are shown for the electrical and sensing properties of several metal oxide nanoparticle ensembles and the influence of porosity is investigated during compaction of nanoparticle powders exposed to an external force. A model describing these properties is developed and it is shown that for a given material only porosity, geometry, and particle size influence the overall electrical properties. The model developed for the description of current transport in particulate matter can also be utilized to describe current-assisted sintering.KeywordsTungsten OxideInkjet PrintingImpedance SpectroscopyZinc Oxide NanoparticlesNanoparticle ArrayThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.