Naumenko D. Photoelectric properties of metal-semiconductor contact with the fullerite, organic semiconductor or nanoparticles intermediate layer.

This thesis is devoted to the influence of intermediate active layer on the photocurrent formation mechanism in metal-semiconductor contact in cases where as the active layer used: thin fullerite films or organic semiconductor films, in which additional electron-hole pairs are generated due to light absorption; metal nanoparticles, in which local plasmons (particular type of quasiparticles) are excited. As a result of investigation the contribution of active layers in the photocurrent of metal-semiconductor surface-barrier structures is determined. It is shown, that the introduction of a thin fullerite intermediate layer in metal-semiconductor structure with flat or microrelief interface leads to the photocurrent increase due to additional generation of charge carriers in the C60 fundamental absorption region. Such structures demonstrate the good time stability. The using of chemically polymerized fullerite films promotes the formation of stable and homogeneous metal nanoparticles on these surfaces. The hopping mechanism of the current-transport in C60 layer was supplemented with Poole-Frenkel emission process on trapping centers, with the barrier height which is greater for the chemically polymerized fullerite films. It is shown, that inorganic semiconductor surface texturing (by chemical anisotropic etching) of organic/inorganic semiconductor heterojunctions leads to the significant photocurrent increase. The excitation of local (surface) plasmons in gold nanoparticles on the semiconductor surface was investigated, and the contribution of local plasmons into the photocurrent of surface-barrier structures Au/GaAs with an intermediate layer of gold nanoparticles at the interface was demonstrated.