Dominant acceptors in Li doped, magnetron deposited Cu2O films

Cu2O films deposited by reactive magnetron sputtering with varying Li concentrations have been investigated by a combination of temperature-dependent Hall effect measurement and thermal admittance spectroscopy. As measured by secondary ion mass spectrometry, Li concentrations up to 5x1020 Li/cm3 have been achieved. Li doping significantly alters the electrical properties of Cu2O and increases hole concentration at room temperature for higher Li concentrations. Moreover, the apparent activation energy for the dominant acceptors decreases from around 0.2 eV for undoped or lightly doped Cu2O down to as low as 0.05 eV for higher Li concentrations.

Investigation of defects in structures based on BP/Si heterojunction

In this work the properties of the BP/Si heterojunction interface were investigated by capacitance methods, the deep levels transient spectroscopy method and admittance spectroscopy. Admittance spectroscopy did not detect any defects, but the deep level transient spectroscopy showed response with activation energy of 0.33 eV and capture cross-section σn=(1-10)·10-19 cm2 and defect concentration (NT) is in the order of 1013 cm-3. This defect level is a trap for electron with position of 0.33 eV below the conduction band in region near the BP/Si interface.

DETECTION OF FALSIFICATION OF HORILKA BY ADMITTANCE SPECTROSCOPY

The methods of quality control of horilka by electrical parameters, in particular, dielectric constant, specific conductivity, and imitation components are analyzed. The research results of individual samples of alcohol solutions and horilkas of different brands by the method of admittance spectroscopy were also analyzed. Based on this, methods for detecting falsification of horilka products by the method of admittance spectroscopy are proposed. The reactive component of the control object's ad is selected as an informative parameter. Two types of falsification are analyzed. The first is the falsification of the original horilka by replacing it with an aqueous-alcohol solution. The second - by replacing one brand of horilka with another. The analysis of the obtained results of researches of two types of objects on reactive components of their admittance in the frequency range 100 Hz100 kHz showed the following: characteristic features of dependencies of reactive components on frequency are revealed; they have been found to have extreme values at different frequencies. The reactive component of the admittance of aqueous-alcohol solutions reaches an extreme value at the beginning of the range. The same component of the original horilkas of different brands has extreme values at the end of the range. Based on this, methods for prompt detection of falsifications are proposed.

Исследование свойств солнечных элементов на основе селективного контакта MoO-=SUB=-x-=/SUB=-/Si с помощью спектроскопии полной проводимости

The possibility of using admittance spectroscopy to characterization the quality of ITO/MoOx/n-Si structures is shown. It has been demonstrated that magnetron sputtering of ITO layer at room temperature leads to radiation defects formation in the near-surface region of Si near the MoOx/Si interface with a depth of 0.13 and 0.26 eV below the conduction band with a capture cross-sectional area of (1–5)∙10^-19 and (5–10)∙10^-19 cm^-2, respectively. An increase in the deposition temperature of the ITO layer to 130 °C allows to reduce the concentration below the sensitivity leading to a significant improvement of solar cells characteristic.