Volodymyr V. Lysak

An experimental study aimed at developing the method of the spontaneous synthesis of InGaN/GaN nanowires formed as radial heterostructures by molecular-beam epitaxy is reported. By means of electron microscopy, it is shown that a wedge-shaped crack can be formed at an In content x = 0.4 and 0.04 in the core and shell, respectively. On the basis of the model of internal structural stresses, a formula is proposed to estimate the critical dimensions and composition for the formation of cracks in nanowires. Comparison of the estimates with the experimental morphology data shows good agreement between them.

Особенности структурных напряжений в нитевидных нанокристаллах InGaN/GaN

InGaN/GaN nanorod structure is presented for the fabrication of light-emitting diodes by means of plasma-chemical etching. Processes of the etching of nanorods and the defect passivation in a...

The properties of the hybrid energy sources “piezoelectric nanogenerator-solar cell” based on GaAs nanowires with the wurtzite crystal structure were investigated. Measurements were performed by the...

Generation of electric current is observed when GaAs nanowires with wurtzite crystal structure are bent by the probe of an atomic force microscope. The current originates from a piezo active phase in the nanowires due to the piezoelectric effect. Increasing of the piezo‐potential in bent nanowires enhances tunneling through the probe–nanowire Schottky barrier due to the thermionic field emission. Laser illumination amplifies short‐circuit current pulses by two orders of magnitude from 9 pA to 1 nA due to the piezo‐phototronic effect. Utilization of such piezo‐phototronic effect in GaAs nanowires is a solution to accelerate the efficiency of hybrid energy sources “piezoelectric nanogenerator − solar cell” comprised of III–V nanowires.

InGaN/GaN nanorod structure for light emission diode fabricated by the reactive plasma etching through the self-assembled Ni nano-cluster mask is presented. Fabricated array structure, presented in the form of truncated cones with average diameter height and period of nanorods is 250±50 nm, 430nm and 650±50 nm, respectively. The side angle of single structure about 80^o. EL spectrum has maximum at 460 nm.

The FDTD optical distribution model in the quasi single dimensional nanostructures is presented. The polar diagram is analyzed for nanowire structure with various diameters. The main conditions for the maximum output in vertical (0° and 180°), horizontal (90°) and leaky mode (30°, 60° and 165°) directions are discussed. Theoretical data show good agreement with experiments.