Ilchenko V. Electrophysics properties of semiconductor heterostructures with the layers of quantum dots and quantum wells

It was shown that admittance spectroscopy (AS) and deep level transient spectroscopy (DLTS) are the methods of choice for the effective diagnostics of structures with QDs to control quality of the layers of QDs, to clearly differentiate the deep levels nature, and reveal reliably defects in structures with the layers of QDs. It has been shown that charge storage in the layers of the quantum dots (QD) placed in the area of spatial charge region (SCR) of diodes of Schottky and p-n junction substantially influences the capacitance-voltage dependences (C-V) of these structures. It has been demonstrated that there are areas with the negative constituent of differential capacitance (NDC) on C-V curves of these structures, due to the recharge of quantum-sized levels of InAs QDs in GaAs and Ge QDs in Si, within the range of frequencies from 0,4 kHz to 1 MHz. It was predicted by theoretical calculations that the NDC effect should be experimentally observed at room temperature, and it indeed was obtained for the first time. A new method of determination of parameters of QDs based on model calculations for frequency dependences followed by analysis of areas with NDC on C-V curves was proposed. It was demonstrated that the pretreatment of Si surface by the B (Borum) atoms using the method of chemical vapor deposition (CVD) facilitates the growth of layers with high quality Ge QDs in Si. The peculiarities of memorizing effect were studied in the structures with nanoclusters of Si in SiO2, prepared by method of the high temperature annealing of SiOX layers, x<2. It was shown for the first time that electric charge storage in the layers of InAs QDs, placed nearby to the 2D electronic channel with high mobility in heterostructure GaAs/AlGaAs, leads to the NDC areas on C-V, measured between a Gate and Source at room temperature, and substantially influences the conductivity of the 2D channel on hetero-boundary of GaAs/AlGaAs. The influence of recharge of quantum-sized levels of InAs QDs on the field-effect transistors (FET) structures with one layer of InAs QDs, placed in the middle of GaAs SCR layer under the metallic Gate electrode, was experimentally demonstrated. The existence of non-linearity part with high coefficient value of direct branch of Schottky diode I-V curves for double barrier tunnel-resonant structures (DBRTS) from AlGaAs barriers in GaAs was clearly demonstrated. A mechanism of electron excitation transfer was suggested and experimentally proved for the GaN(Eu3+) of light-emitting diodes with the several InGaN quantum wells(QW). This mechanism explains the shift of spectral maximum.