Charge diffusion noise in monocrystalline PbS nanoparticle films

摘要

Charge transport in monocrystalline lead sulfide (PbS) nanoparticle films is investigated by current noise measurements. Monocrystalline and single-sized PbS nanoparticles are synthesized via the gas phase and deposited electrostatically onto semiconducting (GaAs) and on isolating (SiN_(x)) substrates with planar electrode contacts. The particles form inhomogeneous films. Low-frequency current noise of 1-ML-thick films are measured at various voltages, exhibiting diffusion noise characteristics, which indicates a random-walk (diffusion) phenomenon of electrons between the particles.