are called dopants
Doping a semiconductor provides additional charge carriers to the material. The dopant atoms are easily ionized, and this provides the semiconductor with either free electrons in the conduction band or electron vacancies (or holes) in the valence band, both of which allow the semiconductor to conduct electricity.
Semiconductors: When temperature increases, more electrons jump to conduction band from valance bond. Hence resistance decreases. Metals: Already plenty of electrons are there in conduction band. When temperature increases, the electrons in conduction band of metal vibrate and collide each other during their journey. Hence the the resistance of metal increases with increase of temperature. S.Lakshminarayana
at higher values of temperature the intrinsic carrier concentration become comparable to or greater than doping concentration in extrinsic semiconductors. thus majority and minority carrier concentration increases with increase in temperature and it behaves like intrinsic semiconductor.
NO. In a semiconductor the resistance decreases with increase of temperature. It is their natural behavior unlike conductors and insulators. If we decrease the temperature their resistance increases. At 0 degree kelvin all semiconductors will act like perfect insulators.
It is called as DOPING. Doping is the process in which you add an impurity to a pure semiconductor to increase its conductivity. While doping is done, crystal structure of semiconductor is not disturbed.
The increase in temperature provides more thermal energy to the electrons in a semiconductor, allowing them to overcome the energy barriers and move more freely, increasing the conductivity. This is due to more electrons being excited to the conduction band and contributing to the electrical conduction of the material.
Doping a semiconductor provides additional charge carriers to the material. The dopant atoms are easily ionized, and this provides the semiconductor with either free electrons in the conduction band or electron vacancies (or holes) in the valence band, both of which allow the semiconductor to conduct electricity.
Semiconductors: When temperature increases, more electrons jump to conduction band from valance bond. Hence resistance decreases. Metals: Already plenty of electrons are there in conduction band. When temperature increases, the electrons in conduction band of metal vibrate and collide each other during their journey. Hence the the resistance of metal increases with increase of temperature. S.Lakshminarayana
Dromotropic effect is the effect on conduction of current. It could be positive or negative depending on the final outcome. A negative dromotropic effect would mean decrease in conduction activity of current while positive would mean increase in conduction activity of current.
An increase in body temperature can lead to faster conduction speed of electrical impulses in the body due to improved nerve function and reduced resistance in the nerve fibers. Conversely, a decrease in body temperature can slow down conduction speed as nerve function is impaired.
With the increase in temperature, the concentration of minority carriers starts increasing. Eventually, a temperature is reached called the critical temperature (85° C in case of germanium and 200° C in case of silicon) when the number of covalent bonds that are broken is very large and the number of holes is approximately equal to number of electrons. The extrinsic semiconductor now behaves essentially like an intrinsic semi-conductor.
The electrical conductivity of pure silicon is very low because it is a semiconductor with a full valence band and an energy gap between the valence and conduction bands. In its pure form, silicon does not have enough free electrons to conduct electricity effectively. doping silicon with other elements can increase its conductivity.
With the increase in temperature if the resistance increases or the current in the circuit decreases then it is said to be have positive temperature coefficient .But in semi-conductors with the increase in temperature the electrons present in the valance band are excited and they would enter the conduction band for conduction . As the no. of charge carriers always increase in a semi-conductor , implies that the current always increases with the increase in temperature so the semi-conductor can never have positive temperature coefficient
Doping a semiconductor means to introduce impurities to the semiconductor in order to alter it. For the most part, doping a semiconductor increases its conductivity.
The conductivity depends on the passage of charged particles especially electrons. In metals electrons are easily available in conduction band and so its conductivity is high. As we increase the temperature then core of atoms vibrate largely. So with positive charge it could easily minimize the electrons in the conduction band and hence fall in conductivity In case of semiconductor there will be usually forbidden gap between valence band and conduction band. So conduction is poor at ordinary temperature. But as we increase temperature that would allow electrons to reach conduction band as covalent bonds get broken. Hence higher conductivity
conductivity of semiconductors increases with increase in temperature as breakdown of covalent bonds take place in the semiconductor due to increase in temp but more & more increase in the temp may result in the breakdown or damage of the semiconductor which results in the decrease in conductivity of semiconductor
increase conduction of heart