| Abstract [eng] |
The goal of this dissertation work was to develop pulsed terahertz radiation techniques and use them to study different properties of the semiconductor materials and semiconductor devices. Three groups of materials were investigated: GaAsBi, GaAs nanowires, copper-indium chalcogenide. The used techniques are THz-TDS, optical pump – THZ probe, optical pump – optical probe and THz excitation spectral measurements. The main results that were presented in this dissertation are the following: thermal annealing has resulted in the shortening of electron lifetime in GaAsBi to picosecond values, which is important achievement for the application of this material in THz range components. In GaAsBi layers with larger than 10% Bi content absorption bleaching recovering on the picosecond time scale and its saturation can be realized when the wavelengths of the optical signals are as long as 1600 nm. The results of these studies can be applied in the production of SESAM with bismide absorption layer. The samples with GaAs nanowires emit THz radiation several times better than the bulk GaAs substrates due to enhanced light absorption because of localized surface plasmon resonances in GaAs nanowires. THz emission efficiency from thin copper-indium chalcogenide layers strongly depends on their stoichiometry and on the parameters of the top transparent contact layers, thus it can be used for the mapping of built-in electric fields in solar cells made from these layers. |
