This blog is for the purpose of my class ELE431. This blog is used for discussion forum on any topics in Solid State Devices. Students may post any topics that is related to the subject.
7/15/08
Chapter 2
Explain why there are very few intrinsic concentration in extrinsic semiconductor compared to dopant concentartion.
An intrinsic semiconductor,is a pure semiconductor without any significant dopant species present.An extrinsic semiconductor is a semiconductor that has been doped involves adding dopant atoms to an intrinsic semiconductor.
Semiconductor doping is the process that changes an intrinsic semiconductor to an extrinsic semiconductor.Impurity atoms act as either donors or acceptors to the intrinsic semiconductor, changing the electron and hole concentrations of the semiconductor.
In extrinsic semiconductors the larger electron concentration than hole concentration are known as n-type semiconductors. In n-type semiconductors, electrons are the majority carriers and holes are the minority carriers. The Fermi energy level also greater than the intrinsic semiconductor and lies closer to the conduction band than the valence band. That's why there are few intrinsic in extrinsic semiconductor.
An extrinsic semiconductor can be formed from an intrinsic semiconductor by added impurity atoms to the crystal in a process known as doping . Impurities, which referred to as dopants, add extrinsic properties to the semiconductor, compared with the properties intrinsic to the pure material itself. An intrinsic semiconductor has equal concentrations of electrons and holes. At sufficiently high temperatures, the intrinsic carrier concentration becomes so large that the effect of a fixed amount of impurity atoms in the crystal is comparatively small and the semiconductor becomes intrinsic. When the carrier concentration is predominantly determined by the impurity content, the conduction of the material is said to be extrinsic. It makes the concentration in intrinsic semiconductor is very few compared to extrinsic.
as far as i know that intrinsic semiconductor contains no impurities and no crystalline defects.so that the concentration of electron in conduction band and the concentration of holes in the valence band is equal. n=p=ni.....(i) the semiconductor can be extrinsic by adding dopant atoms.so the number of concentration not equal.extrinsic semiconductors are created by incorporating impurity atoms into the intrinsic semiconductor in doping process.dopant atoms can be donors or accceptors.
n>p...n type semiconductor-negative charged electrons
p>n...p type semiconductor-positive charged holes.
Intrinsic semiconductor contains no impurities and no crystalline defects.so that the concentration of electron in conduction band and the concentration of holes in the valence band is equal n=p=ni.Extrinsic is by adding dopant atoms.So this is why the the number of concentration not equal.Dopant can be donor or acceptor
An intrinsic semiconductor is a pure semiconductor that contains no impurities and no crystalline defects. An extrinsic semiconductor is a semiconductor that has been doped involves adding dopant atoms to an intrinsic semiconductor.
zuraini muhammad @ mohamed shaari 2007121763 eeb4f
i think to satisfied n not equal to p condition .. and to avoid the extrinsic material to become instrinsic material..and also the instrinsic material can have a doping process with high volume dopant material(imstrinsic material also)
intrinsict is a pure one s/c extrinsict is an impurity s/c the dopant concentration more higher than the intrinsict s/c in extrinsict s/c because the at room temp. the weakly bound electron is readily freed as a carrier and the electron concentration will increase.
intrinsic s/c is pure s/c with no impurities while extrinsic is vice versa from that.for intrinsic,n=p=ni.hence for extrinsic n>p.intrinsic s/c can be form to extrinsic by dopping process.that is why the concentration for both s/c are not same.
based on thr lecture before, intrinsic behaviour of pure material semiconductor and doped marterial at high temperature is characterized by exponentially activated conductivity. While, extrinsic behaviour is suitable doped material by contrast is characterized by a majority carrier concentration sensibly independent of temperature over useful operating range of temperature.The high temperature end of extrinsic range is higher for silicon with larger bandgap.The extrinsic majority carrier concentration is equal to net doping concentration[ND-NA].
In an extrinsic semiconductor material,the majority carrier concentration are numbers that represent the electron that are freed from the donors or holes due to acceptors.instrinsic carrier electron and holes still exist but are smaller in numbers and thus are assume negligible compare to majority carrier due to the dopant.
An extrinsic s/c is a s/c when we doped intrinsic s/c with donor atom or acceptor.So,when we have this extrinsic s/c, the intrinsic concentration will reduced depends on donor or acceptor concentration... For n-type s/c,Nd>ni For p-type s/c,Na>ni For intrinsic s/c,ni=no=po
An extrinsic s/c is a s/c when we doped intrinsic s/c with donor atom or acceptor.So,when we have this extrinsic s/c, the intrinsic concentration will reduced depends on donor or acceptor concentration... For n-type s/c,Nd>ni For p-type s/c,Na>ni For intrinsic s/c,ni=no=po
In an extrinsic semiconductor material,the majority carrier concentration are numbers that represent the electron that are freed from the donors or holes due to acceptors.instrinsic carrier electron and holes still exist but are smaller in numbers and thus are assume negligible compare to majority carrier due to the dopant. An extrinsic s/c is a s/c when we doped intrinsic s/c with donor atom or acceptor.So,when we have this extrinsic s/c, the intrinsic concentration will reduced depends on donor or acceptor concentration... For n-type s/c,Nd>ni For p-type s/c,Na>ni For intrinsic s/c,ni=no=po
In an intrinsic semiconductor, a region is electrically neutral if the concentration n of conduction electrons is equal to the concentration p of holes. Any deviation in the balance gives a space charge equal to e(p − n), where e is the charge on an electron. In an extrinsic semiconductor, ionized donor atoms give a positive space charge and ionized acceptor atoms give a negative space charge
Extrinsic is by adding dopant atoms.So this is why the the number of concentration not equal.Dopant can be donor or acceptor
Intrinsic semiconductor contains no impurities and no crystalline defects.so that the concentration of electron in conduction band and the concentration of holes in the valence band is equal n=p=ni.
n>p...n type semiconductor-negative charged electrons
p>n...p type semiconductor-positive charged holes.
S/c doping is the process that changes an intrinsic s/c to an extrinsic s/c.In extrinsic s/c the larger electron concentration than hole concentration are known as n-type s/c. In n-type s/c, electrons are the majority carriers and holes are the minority carriers. The Fermi energy level also greater than the intrinsic semiconductor and lies closer to the conduction band than the valence band.
/*MOHD UBAIDILLAH BIN SHAMSUDIN*/ /*2007126591*/ /*EEB4E*/
When an intrinsic s/c is doped with an extrinsic s/c with donor atom or acceptor.So, the intrinsic concentration will reduced depends on donor or acceptor concentration :
1. For extrinsic : n-type s/c, no > po p-type s/c, po > no
Intrinsic semiconductor contains no impurities and no crystalline defects.Extrinsic semiconductor is a semiconductor that has been doped involves adding dopant atoms to an intrinsic semiconductor.
25 comments:
in intrinsic material,n=p,while in extrinsic material n>p, is this the answer puan?
An intrinsic semiconductor,is a pure semiconductor without any significant dopant species present.An extrinsic semiconductor is a semiconductor that has been doped involves adding dopant atoms to an intrinsic semiconductor.
Dayang Maslin Hj Bukari
2007270442
EEB4E
Semiconductor doping is the process that changes an intrinsic semiconductor to an extrinsic semiconductor.Impurity atoms act as either donors or acceptors to the intrinsic semiconductor, changing the electron and hole concentrations of the semiconductor.
In extrinsic semiconductors the larger electron concentration than hole concentration are known as n-type semiconductors. In n-type semiconductors, electrons are the majority carriers and holes are the minority carriers. The Fermi energy level also greater than the intrinsic semiconductor and lies closer to the conduction band than the valence band. That's why there are few intrinsic in extrinsic semiconductor.
*Zaitiakmar Farhana bt. Ameran
*2007292004
*EEB4E
An extrinsic semiconductor can be formed from an intrinsic semiconductor by added impurity atoms to the crystal in a process known as doping . Impurities, which referred to as dopants, add extrinsic properties to the semiconductor, compared with the properties intrinsic to the pure material itself. An intrinsic semiconductor has equal concentrations of electrons and holes. At sufficiently high temperatures, the intrinsic carrier concentration becomes so large that the effect of a fixed amount of impurity atoms in the crystal is comparatively small and the semiconductor becomes intrinsic. When the carrier concentration is predominantly determined by the impurity content, the conduction of the material is said to be extrinsic. It makes the concentration in intrinsic semiconductor is very few compared to extrinsic.
as far as i know that intrinsic semiconductor contains no impurities and no crystalline defects.so that the concentration of electron in conduction band and the concentration of holes in the valence band is equal.
n=p=ni.....(i)
the semiconductor can be extrinsic by adding dopant atoms.so the number of concentration not equal.extrinsic semiconductors are created by incorporating impurity atoms into the intrinsic semiconductor in doping process.dopant atoms can be donors or accceptors.
n>p...n type semiconductor-negative charged electrons
p>n...p type semiconductor-positive charged holes.
Intrinsic semiconductor contains no impurities and no crystalline defects.so that the concentration of electron in conduction band and the concentration of holes in the valence band is equal n=p=ni.Extrinsic is by adding dopant atoms.So this is why the the number of concentration not equal.Dopant can be donor or acceptor
An intrinsic semiconductor is a pure semiconductor that contains no impurities and no crystalline defects. An extrinsic semiconductor is a semiconductor that has been doped involves adding dopant atoms to an intrinsic semiconductor.
zuraini muhammad @ mohamed shaari
2007121763
eeb4f
i think to satisfied n not equal to p condition .. and to avoid the extrinsic material to become instrinsic material..and also the instrinsic material can have a doping process with high volume dopant material(imstrinsic material also)
~~2007126643~~
intrinsict is a pure one s/c
extrinsict is an impurity s/c
the dopant concentration more higher than the intrinsict s/c in extrinsict s/c because the at room temp. the weakly bound electron is readily freed as a carrier and the electron concentration will increase.
Siti Aminah
EEB4F
intrinsic s/c is pure s/c with no impurities while extrinsic is vice versa from that.for intrinsic,n=p=ni.hence for extrinsic n>p.intrinsic s/c can be form to extrinsic by dopping process.that is why the concentration for both s/c are not same.
based on thr lecture before, intrinsic behaviour of pure material semiconductor and doped marterial at high temperature is characterized by exponentially activated conductivity. While, extrinsic behaviour is suitable doped material by contrast is characterized by a majority carrier concentration sensibly independent of temperature over useful operating range of temperature.The high temperature end of extrinsic range is higher for silicon with larger bandgap.The extrinsic majority carrier concentration is equal to net doping concentration[ND-NA].
That is all what i know so far.Thank you.
NURAIN BINTI HASHIM
GROUP EEB5E
2007270538
Intrinsic semiconductor-no impurities and no crystalline defects.
n= no. of electron per cm3
p= no. of hole per cm3
n=p=ni
Extrinsic semiconductor - is a semiconductor that has been doped involves adding dopant atoms to an intrinsic semiconductor.
Hazim
2007270806
EEB4F
In an extrinsic semiconductor material,the majority carrier concentration are numbers that represent the electron that are freed from the donors or holes due to acceptors.instrinsic carrier electron and holes still exist but are smaller in numbers and thus are assume negligible compare to majority carrier due to the dopant.
mohd ikhwan
2007290828
eeb4e
as many as dopant concentration that can been put in the material..and the material could make a bonding with dopant material..~2007126643~
An extrinsic s/c is a s/c when we doped intrinsic s/c with donor atom or acceptor.So,when we have this extrinsic s/c, the intrinsic concentration will reduced depends on donor or acceptor concentration...
For n-type s/c,Nd>ni
For p-type s/c,Na>ni
For intrinsic s/c,ni=no=po
An extrinsic s/c is a s/c when we doped intrinsic s/c with donor atom or acceptor.So,when we have this extrinsic s/c, the intrinsic concentration will reduced depends on donor or acceptor concentration...
For n-type s/c,Nd>ni
For p-type s/c,Na>ni
For intrinsic s/c,ni=no=po
shahizawanis bt shamshuri
2006687187
EEB4A
In an extrinsic semiconductor material,the majority carrier concentration are numbers that represent the electron that are freed from the donors or holes due to acceptors.instrinsic carrier electron and holes still exist but are smaller in numbers and thus are assume negligible compare to majority carrier due to the dopant.
An extrinsic s/c is a s/c when we doped intrinsic s/c with donor atom or acceptor.So,when we have this extrinsic s/c, the intrinsic concentration will reduced depends on donor or acceptor concentration...
For n-type s/c,Nd>ni
For p-type s/c,Na>ni
For intrinsic s/c,ni=no=po
my skema (^_^)
Intrinsic =pure s/c cz without any doping.
Extrinsic =unpure s/c cz s/c with doped adding atom.
Izuan 2007126589 clas e
In an intrinsic semiconductor, a region is electrically neutral if the concentration n of conduction electrons is equal to the concentration p of holes. Any deviation in the balance gives a space charge equal to e(p − n), where e is the charge on an electron. In an extrinsic semiconductor, ionized donor atoms give a positive space charge and ionized acceptor atoms give a negative space charge
2007121889
Extrinsic is by adding dopant atoms.So this is why the the number of concentration not equal.Dopant can be donor or acceptor
Intrinsic semiconductor contains no impurities and no crystalline defects.so that the concentration of electron in conduction band and the concentration of holes in the valence band is equal n=p=ni.
n>p...n type semiconductor-negative charged electrons
p>n...p type semiconductor-positive charged holes.
“MUHAMAD IZUAN BIN IBRAHIM”
“2007126589”
“EEB4E”
S/c doping is the process that changes an intrinsic s/c to an extrinsic s/c.In extrinsic s/c the larger electron concentration than hole concentration are known as n-type s/c. In n-type s/c, electrons are the majority carriers and holes are the minority carriers. The Fermi energy level also greater than the intrinsic semiconductor and lies closer to the conduction band than the valence band.
/*MOHD UBAIDILLAH BIN SHAMSUDIN*/
/*2007126591*/
/*EEB4E*/
When an intrinsic s/c is doped with an extrinsic s/c with donor atom or acceptor.So, the intrinsic concentration will reduced depends on donor or acceptor concentration :
1. For extrinsic :
n-type s/c, no > po
p-type s/c, po > no
2. For intrinsic s/c :
ni = no = po
mohd khairul anuar bin awang
2007121771
eeb4e
Intrinsic semiconductor contains no impurities and no crystalline defects.Extrinsic semiconductor is a semiconductor that has been doped involves adding dopant atoms to an intrinsic semiconductor.
Post a Comment