About the Possibility of the Bulk Thermo Gradient Effect Use for the Creation of the Effective Thermobattery

The theoretical basis has been developed and the idea of practical production and testing the semiconductor electric generator (thermobattery) of a new type acting on the basis of a metal – semiconductor system has been offered. It is shown that the thermobattery will work on the basis of the use of a bulk thermogradient effect. Such effect allows to gain a sufficient level of generated power from one unit of the whole volume of a semiconductor material. When using the semiconductor thermobattery together with solar and wind electric generators, it is possible to simplify significantly constructional and technological features of these installations

Homo- and Hetero-Structure Formation in Semiconductors by Laser Radiation: First Stage of Quantum Cones Formation

A possibility of formingquantum cones (QC) by Nd:YAG laser radiation on the surface of semiconductorssuch as Si and Ge crystals, and SiGe and CdZnTe solid solutions has been shown.A two-stage mechanism of quantum cone formation has been proposed. The first stage is generation and redistribution of point defects (impurity atoms and intrinsic point defects – vacancies and self-interstitials) in a temperature gradient field, the so-called thermogradient effect. As a result a new phase is formed on the irradiated surface, for example a Ge phase forms on the surface of a SiGe solid solution. The second stage is characterized by mechanical plastic deformation of the strained top layer leading to the formation of quantum cones, due to selective laser radiation absorption of the top layer. The first stage is more difficult for understanding of the physical processes which takeplace during of growth of QC, especially in pure intrinsic elementary semiconductors (Ge, Si) and compounds (CdTe, GaAs). Therefore, this research is focused on the investigation of the first stage of QC formation by laser irradiation. As a result of the investigation, a new mechanism for p-n junction formation in the elementary semiconductors and heterojunction in solid solutions by laser radiation as a first stage of QC formation is proposed.

Influence of Laser Radiation on Optical Properties and Surface Structure of CdZnTe Crystal

The change of surface of Cd0.9Zn0.1Te crystal morphology after irradiation by pulsed Nd:YAG laser has been studied. Thermogradient effect (TGE) has the main role in the interaction process of laser radiation with semiconductors. A change of the irradiated surface relief has been observed by atom force microscope. Self-organizing nano-cones are observed on the irradiated surface of Cd0.9Zn0.1Te crystal at intensity of the laser in the range of 4.0 – 12.0 MW/cm2. A graded band gap structure with optical window was formed at the top of nano-cones.

Suppression of Pores Formation on a Surface of p-Si by Laser Radiation

The influence of strongly absorbing N¬2 laser radiation on pores formation on a surface of Si single crystal has been investigated using optical microscope, atomic force microscope and photoluminescence. After irradiation by the laser and subsequent electrochemical etching in HF acid solution morphological changes of the irradiated parts of a surface of Si were not observed. At the same time, pores formation on the non-irradiated parts of Si surface took place. The porous part of the Si surface is characterized by strong photoluminescence in red part of spectra with maximum at 1.88 eV and intensity of photoluminescence increases with current density. Suppression of the pores formation by the laser radiation is explained with inversion of Si type conductivity from p-type to n-type. This fact is explained by Thermogradient effect – generation and redistribution of the intrinsic defects in gradient of temperature. It was shown that the depth of n-Si layer on p-Si substrate depends on intensity of laser radiation and it increases with intensity of laser radiation. The results of the investigation can be used for optical recording and storage of information on surface of semiconductors.