semiconductors
germanium low sensitivity
Deflection of moving carriers in a semiconductor perpendicular to a magnetic field.
hall coefficient of a lightly doped semiconductor will decrease with increase in temp as hall coefficient is inversely proportional to number density of charge carriers.
if hall voltage is positive then it is p-type & if it is negative then it is n-type semiconductor.
If a semiconductor carrying a current ( I ) is placed in a transverse magnetic field ( B ), an electric field ( E ) is induced in the direction perpendicular to both I & B.This is called hall effect.for full explanation visit http://www.ecematerials.com/2013/07/hall-effect.html
A Hall Effect sensor is a transducer that varies its output voltage in response to a magnetic field.In its simplest form, the sensor operates as an analog transducer, directly returning a voltage. Hall Effect Sensors consist basically of a thin piece of rectangular p-type semiconductor material such as gallium arsenide (GaAs). When the device is placed within a magnetic field, the magnetic flux lines exert a force on the semiconductor material which deflects the charge carriers, electrons and holes, to either side of the semiconductor slab. This movement of charge carriers is a result of the magnetic force they experience passing through the semiconductor material. As these electrons and holes move side wards a potential difference is produced between the two sides of the semiconductor material by the build-up of these charge carriers. The effect of generating a measurable voltage by using a magnetic field is called the Hall Effect. Hall Effect sensors and switches are designed to be in the "OFF" when there is no magnetic field present. They only turn "ON", when subjected to a magnetic field of sufficient strength and polarity.There are two basic types of digital Hall Effect sensor, Bipolar and Unipolar. Bipolar sensors require a positive magnetic field (South Pole) to operate them and a negative field (North Pole) to release them while unipolar sensors require only a single magnetic south pole to both operate and release them as they move in and out of the magnetic field. Here we are using a unipolar sensor
A Hall Effect sensor is a transducer that varies its output voltage in response to a magnetic field.In its simplest form, the sensor operates as an analog transducer, directly returning a voltage. Hall Effect Sensors consist basically of a thin piece of rectangular p-type semiconductor material such as gallium arsenide (GaAs). When the device is placed within a magnetic field, the magnetic flux lines exert a force on the semiconductor material which deflects the charge carriers, electrons and holes, to either side of the semiconductor slab. This movement of charge carriers is a result of the magnetic force they experience passing through the semiconductor material. As these electrons and holes move side wards a potential difference is produced between the two sides of the semiconductor material by the build-up of these charge carriers. The effect of generating a measurable voltage by using a magnetic field is called the Hall Effect. Hall Effect sensors and switches are designed to be in the "OFF" when there is no magnetic field present. They only turn "ON", when subjected to a magnetic field of sufficient strength and polarity.There are two basic types of digital Hall Effect sensor, Bipolar and Unipolar. Bipolar sensors require a positive magnetic field (South Pole) to operate them and a negative field (North Pole) to release them while unipolar sensors require only a single magnetic south pole to both operate and release them as they move in and out of the magnetic field. Here we are using a unipolar sensor
In 1962 robert hall invented semiconductor laser later used in CD players.
If we are given a bar ofsemiconductor(but it is not known whether it is p-type or n-type),by measuring the polarity of the hall voltage between the sides of the given bar, we can determine whether it is n-typeor p-type.
because we have hall cofficient =1/ne. where the n=no of electron ,e=charge of electron. we know that "n "in metal is very large. so that R=HALL COFFICIENT" is very small FOR it .so we can not find sufficient result for hall cofficient so we use semi conductor which gives non zero hall cofficient.
If a semiconductor carrying a current ( I ) is placed in a transverse magnetic field ( B ), an electric field ( E ) is induced in the direction perpendicular to both I & B.This is called hall effect.for full explanation visit http://www.ecematerials.com/2013/07/hall-effect.html