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ZnO crystals on heating acquires the for...

ZnO crystals on heating acquires the formuls `Zn(1+x)O`.
Or
There is an increase in conductivity when silicon doped with phosphorus. Give reason.

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(i)On heating ZnO loses oxygen as `ZnO to Zn^(2+) + 1/2 O_2 + 2e^-`
Excess `Zn^(2+)` ions are entrapped into vacant interstitial sites. Hence, there is metal excess.
(ii)Silicon belongs to Group 14 while phosphorus belongs to Group 15. Hence, in the valence shell, P has one extra electron than Si. When Si is replaced by P atom, due to extra electron, there is increase in conductivity.
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There is an increase in conductivity when Silicon is doped with Phosphorous. Give reason.

ZnO crystal on heating acquires the formula Zn_(1+x) O. Give reason.

Why does the conductivity of silicon increase upon doping with phosphorus ?

Give reason : (a) Why is Frenkel defect found in AgCl ? (b) What is the difference between silicon doped with phosphorus and doped with gallium semi-conductors ?

Doping mens introduction of small amount of impurities like phosphorus , arsenic or boron into the pure crystal . In pure silicon , ther are four valenices used in bonding with other four adjacent silicon crystal is doped with a group -15 element ( with five valence electron ) such as P, As , or Bi , the structure of the crystal lattic remains unchanged . Out of the five valence electron of group -15 doped element four element are used in normal covalent bonding with silicon while fiffth electron is delcoasiled and thus conducts electricity Doping a silicon crystal with a group -13 element (with three valence electrons ) such as B, Al, Ga or In products a semiconductor with three electrons in in dopant . The place where fourth electron is missing is called an electron vacancy or hole . Such hole can move throught the crystal like a positive charge giving rise conduction of electricity. Silicon that has been dopend with group - 15 elements is called :

Doping mens introduction of small amount of impurities like phosphorus , arsenic or boron into the pure crystal . In pure silicon , ther are four valenices used in bonding with other four adjacent silicon crystal is doped with a group -15 element ( with five valence electron ) such as P, As , or Bi , the structure of the crystal lattic remains unchanged . Out of the five valence electron of group -15 doped element four element are used in normal covalent bonding with silicon while fiffth electron is delcoasiled and thus conducts electricity Doping a silicon crystal with a group -13 element (with three valence electrons ) such as B, Al, Ga or In products a semiconductor with three electrons in in dopant . The place where fourth electron is missing is called an electron vacancy or hole . Such hole can move throught the crystal like a positive charge giving rise conduction of electricity. Silicon that has been dopend with group - 13 elements is called :

Doping mens introduction of small amount of impurities like phosphorus , arsenic or boron into the pure crystal . In pure silicon , ther are four valenices used in bonding with other four adjacent silicon crystal is doped with a group -15 element ( with five valence electron ) such as P, As , or Bi , the structure of the crystal lattic remains unchanged . Out of the five valence electron of group -15 doped element four element are used in normal covalent bonding with silicon while fiffth electron is delcoasiled and thus conducts electricity Doping a silicon crystal with a group -13 element (with three valence electrons ) such as B, Al, Ga or In products a semiconductor with three electrons in in dopant . The place where fourth electron is missing is called an electron vacancy or hole . Such hole can move throught the crystal like a positive charge giving rise conduction of electricity. No. of valene electrons in silicon are :

Account for the following : (i) Schottky defects lower the density of related solids. (ii) Conductivity of silicon increases on doping it with phosphorus.

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