Noise measurements and fluctuation analysis in nanoparticle films

This work reports two different ways of study providing potentially important information about nanoparticle films. The first study is about conductance noise in PbS nanoparticle films. Monocrystalline and single-sized PbS nanoparticles are synthesized via the gas-phase and deposited electrostatically onto semiconducting (GaAs) and on isolating (SiNx) substrates with planar electrode contacts. Low frequency current noise of one monolayer thick films are measured at various voltages, exhibiting diffusion noise characteristics, which indicates a random walk (diffusion) phenomenon of electrons between the particles. In the second part of the paper, a new method is proposed which would be is able to predict the particle size of conductive nanoparticle films in situ, during deposition. The method could be used for the measurement of the time-derivative of conductance fluctuations during deposition.