Students lab for transport phenomena in semiconductor structures

Responsible person: Dr. Michał Marchewka

The Laboratory of Transport Phenomena in Semiconductor Structures is to be an integral part of the series of lectures on the phenomenon of electron transport in semiconductor structures within the semiconductor transport semester and the "Physics of low-dimensional structures" conducted in the Technical Physics field now and will be conducted within the planned direction. "Nanotechnology and new materials for aviation". This course falls into the standard of Technical Physics, and laboratory exercises give students the opportunity to experimentally verify theoretical knowledge, and also present the possibility of experimental work and acquaintance with modern measurement techniques in experimental physics.


Description of exercises and apparatus

1) Hall study in semiconductor volumetric in the temperature range 200-1600 C.
Purpose of the exercise: Based on the experimental data obtained during the experiment, the student will determine the type of conductivity of the semiconductor, determining the Hall constant for the material studied, determining the Hall constant dependence on temperature, determining the mobility of the current carriers, determining the concentration of the mass carriers. All these sizes allow for accurate analysis and interpretation of the semiconductor material to be tested for its physical and application properties.

2) Measurement of the total quantum Hall effect and oscillation of magneto resistance at 4.2K.
A measuring stand that will be able to measure the quantum Hall effect and measure the oscillation of magneto resistance at liquid helium (4.2K) temperature in 2D (2D) structures. On the basis of the experimental data, the parameters of the two-dimensional gas current carriers, the concentration and the mobility of the current carriers should be determined. Determine the position of the Fermi level based on the results of the Shubnikova-de Haas oscillation measurements.

3) Determination of e / kB ratio and energy interruption in semiconductors for different temperatures.
Purpose of the exercise: familiarize yourself with the physical foundations of the p-n connector. During the exercise, measurements of the current density of the current flowing through the connector from the applied voltage (characteristic I (V)) will be made for different temperatures. Analysis of the obtained characteristics allows to determine the ratio e / kB and the energy interruption of a given semiconductor (silicon) and its dependence as a function of temperature.

4) Measurement of semiconductor parameters using the LBIC method
LBIC (Laser Beam Induced Current) is a non-destructive photoelectric characterization of microelectronic structures. It consists in studying the structure's current response to light beam excitation. In this method, the focused beam of specified length scans from point to point the surface of the semiconductor sample causing the generation of electron-hole pairs. Using measurement data based on this experience we can determine the diffusion path length. In addition, you can indirectly determine the life span of the excess carriers their speed and recombination.

Investigation of optical and electrical dependence of semiconductors in the temperature range 2K-500K.
Study of the dependence of optically electric semiconductors over a wide temperature range. Measurement results will allow you to determine the optical properties of semiconductors and their applicability over a wide temperature range.