If a current carrying conductor placed in a perpendicular magnetic field, a potential difference will generate in the conductor which is perpendicular to both. We were supposed to observe the hall effect in semiconductors and measure the hall coefficient rh and find the concentration and type of semiconductor. The sample is about 25mm square with a thickness of 0. The hall effect experiment has been used to demonstrate the existence of positive charge carriers in semiconductors. In this experiment the characteristics of an electromagnet were investigated, and then this electromagnet was used to show that the hall voltage v h is directly proportional to the product of the magnetic. Harsh shukla hall sensor hall effect and its applications hall effect thruster 2. Lesson plan hall effect patterson where i is the current, b is the magnetic field in teslas, n is the charge carrier density of the material, q is the fundamental charge, and t is the thickness of the material. The temperature range of this experiment is 77k to 400k at its most extreme. This arrangement keeps the current flow in the foil spatially uniform. In this experiment, the hall effect will be used to study some of the physics of charge transport in metal and semiconductor samples. The hall effect experiment determines the sign of the charge carriers in current flow.
The hall effect in metals and semiconductors in this experiment, students learn about the classical hall effect which is the basis of most sensors used in magnetic field measurements. For most metals, there will be a single charge carrier per atom, and n can be calculated using the molar mass and the density of the material. If a current passes through a conducting material along the x direction and there is a magnetic. For clarity, the original effect is sometimes called the ordinary hall effect to distinguish it from other hall effects which have. Hall angle 5800560054005200500048004600 100 105 110 115 120 125 5 s temperature k hall mobility the mobility of the carrier expected to decrease with temperature efield from hall effect divided by generated efieldwe expect the e field from the hall effect to decrease with temp causing the hall angle to decrese. Hall effect applications of hall effect august, 2018 february 24, 2012 by electrical4u whenever we place a current carrying conductor in a magnetic field, there is a deflection of the charge carriers due influence of magnetic field in the conductor body. Hall e ect measurements of the carrier density and mobility of a 3d electron gas in a gaasalgaas heterostructure d. A foil current is passed through the sample left to right in the photo via the 5wire harnesses. It directly determines both the sign and density of charge carriers in a given sample.
Edwin hall in 1879 while he was a doctoral candidate at johns hopkins university in baltimore. We have assumed so far that the mobile charge carriers within solids are electrons and this is in agreement with the sign of the hall voltage for most materials. The hall effect discovered in 1879 by edwin hall it is the development of a potential difference in a conductor transverse to the current passing. Digital voltmeter is much more convenient to use in hall experiment, because. This is used to select the part of the experiment to perform 1 magnetic field vs current. Chiayib stony brook university graduate physics laboratory dated. Semiconductor hall effect basic concepts, numerical on. The objective of this educational module is to measure the hall effect germanium and determine the carrier concentration and type as a function of temperature. The hall effect is the production of a voltage difference the hall voltage across an electrical conductor, transverse to an electric current in the conductor and to an applied magnetic field perpendicular to the current. Seebeck effect voltages that depend on b and temperature gradient nernst effect voltage v n righileduc effect voltage v r voltages that depends only on i misalignment voltage ohms law v 0 voltages that depend on the product of b and i hall effect voltage v h ettingshausen effect. The determination of the concentration of the charge carriers n or p. Investigating the hall effect in silver objects of the experiment g validation of the proportionality of the hall voltage and the magnetic flux density. Students will measure hall coefficient and carrier charge concentration in a given semiconductor crystal which will help them to understand important concepts in.
Hall effect measurement in germanium electrical transport option prof. First some current 1a is sent through the electromagnet to. Germanium is an indirect bandgap semiconductor with a room temperature. These measurements will enable the student to determine. The hall coefficient is calculated based on experimental results and used to measure fundamental semiconductor properties of the given doped sample of. The hall effect experiment conducted by edwin hall in 1879 determines the sign of the charge carriers in current flow. The hall effect is used extensively to study conduction in materials, particularly in semiconductors. Hall effect applications of hall effect electrical4u. Work purpose the hall effect is one of the most important effects in the determination of the parameters that characterize from the electrical point of view the semiconductor materials. Using a microvoltmeter, we are able to make measurements of the hall voltage across a conductor due to an applied magnetic eld. V hall w is the magnitude of the electric field due to the hall effect. This experiment introduces students to the hall effect which is a fundamental principle of magnetic field sensing.
She hall effect in semiconductor experimentation lab university. The quantity measured in this experiment is not conductivity. Abstract in order to investigate the nature of charge carriers in electric conductors, we carry out an experiment to measure the hall coecients of silver and tungsten. Pdf the hall effect experiment using new data acquisition and. To determine which it actually is, the semiconductor is immersed in the magnetic field. I recently performed this experiment in the solid states lab during the ii semester for m. In this experiment you will measure the re sistivity and the hall coefficient as functions of the temperature, for an. The hall effect and its application in the measurement of. Significance of the hall effect on semiconductors gulpmatrix.
Hall observed that when a currentcarrying conductor is placed in a transverse magnetic eld, the lorentz force on the moving charges produces a potential di erence perpendicular to both the magnetic eld and the electric current. A current can be thought of as a negative charge moving in one direction or as a positive charge moving in the opposite direction. Thin film samples consisting of a semiconductor inas and two different metals aluminum and gold are investigated to determine the sign and density of the. Hall was attempting to verify the theory of electron flow proposed by kelvin some 30 years earlier. In measuring v h, the following is the accurate method. The hall effect is the production of a voltage difference the hall voltage across an electrical. Hall effect experiment utk department of physics and. A current can be thought of as a negative charge moving in one direction fig.
This slider activate only if hall effect setup is selected. The paper briefly describes the hall effect and its application in semiconductor material analysis. Prepare a table that gives the following information. Hall effect is used to calculate the mobility of charge carriers free electrons and holes. Hall e ect measurements of the carrier density and. The hall effect experiment using new data acquisition and processing methods 33 figure 6. California polytechnic state university solid state physics laboratory. In semiconductors, the charge carriers which produce a current when they move may be positively or negatively charged.
In solid state physics, hall effect is an important tool to characterize the materials especially semiconductors. In general, the hall voltage is not a linear function of magnetic field applied, i. Binaural beats concentration music, focus music, background music for studying, study music greenred productions relaxing music 231 watching live now. Hall effect ndoped semiconductor se7260 products pasco.
The importance of the hall effect becomes apparent when semiconductors are used, as we now see. The hall effect is when a magnetic field is applied at right angles to the current flow in a thin film where an electric field is generated, which is mutually perpendicular to the current and the magnetic field and which is directly proportional to the product of the current density and the magnetic induction. And this is used to select the material for finding hall. The hall effect voltage, v h, and hall coefficient, r h, for the same sample will be measured using a magnetic field. Instrument manuals this lab will be graded 30% on theory, 20% on technique, and 50% on analysis.
The magnetic force is f m ev d b where v d is the drift velocity of the charge. The whole system is mounted in a pen type case for further protection. The hall effect was discovered in 1879 by edwin herbert hall while working on his doctoral degree at the johns hopkins university in baltimore, maryland, usa discovered 18. Pdf the hall effect, in all its variants classic, quantum or fractional quantum, is one of the effects that revolutionized certain areas of physics. Hall effect measurement in germanium electrical transport. The crystal is covered by a protective layer of paint. Consider a rectangular conductor of thickness t kept in xy plane.
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