Charge diffusion noise in monocrystalline PbS nanoparticle films

Charge transport in monocrystalline lead sulfide (PbS) nanoparticle films i s investigated by current noise measurements. Monocrystalline and single-si zed PbS nanoparticles are synthesized via the gas phase and deposited elect rostatically onto semiconducting (GaAs) and on isolating (SiNx) substrates with planar electrode contacts. The particles form inhomogeneous films. Low -frequency current noise of 1-ML-thick films are measured at various voltag es, exhibiting diffusion noise characteristics, which indicates a random-wa lk (diffusion) phenomenon of electrons between the particles. (C) 2000 Amer ican Institute of Physics. [S0003-6951(00)03747-5].