Laser-induced semiconductor nanocluster structures on the solid surface: new physical principles to construct the hybrid elements for photonics

Abstract

The laser synthesis technique for producing nanoparticles/nanoclusters of different topology for semiconductor samples (PbTe) is presented by two laser ablation methods: direct laser modification of thin films and laser evaporation of substance from the target in liquid (ethanol) to produce a colloidal system, and the subsequent laser deposition of the particles from colloid on solid substrate [under continuous wave (cw)-laser, λ = 1.06 μm, laser intensity—up to 106 W/cm2]. Electro-physical properties of the induced structures have been controlled by various induced topology. It is obtained that electroresistance can dramatically decrease due to spontaneous selected multichannel/parallel electron transportation trajectories in the inhomogeneous cluster system. Two conditions are principal for that: the characteristic cluster size a < l, where l is the inelastic length, and distance d between two neighboring clusters must be less than de Broglie wavelength λdB. So, the tunneling quantum effect takes place between correlated particles in two domains. Jump conductivity has also been detected under some experimental conditions for laser-induced cluster structures. The cluster shell model can be taken into account to explain the experimental results. For such laser-induced nanostructures we demonstrated the tendency of superconductivity to increase the electrical conductivity by several times (at room temperature) in our case as compared to the homogenous monolithic sample. The fact can be explained by analogy with the correlated particles/coupling pairs. Such approach is of great significance for constructing the elements and devices of optoelectronics and photonics in hybrid circuits on new physical principles.