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.
9/3/08
Chapter 5 (cont...)
What is the different between forward bias and reverse bias?
forward bias:at forward biased,the polarity voltage applied(Va) to the np s/c is same as np side polarity as example:http://en.wikipedia.org/wiki/Image:PN_Junction_in_Forward_Bias.png at forward biased,the junction voltage(Vj) is smaller than zero bias(Vbi) by Vj=Vbi-Va,forward bias Va is (+).
reversed bias:at reversed bias,the polarity voltage applied(Va) to the np s/c is opposite to the polarity np s/c as example:http://en.wikipedia.org/wiki/Image:PN_Junction_in_Reverse_Bias.png
at reversed bias,the junction voltage(Vj) is higher than built-in voltage(Vbi) by Vj=Vbi-Va,reversed bias Va is (-) so,Vj=Vbi+Va. ~~2007126643~~ eeb4f
A p-n diode with an applied bias voltage, Va. A forward bias corresponds to applying a positive voltage to the anode (the p-type region) relative to the cathode (the n-type region). A reverse bias corresponds to a negative voltage applied to the cathode. The applied voltage is proportional to the difference between the Fermi energy in the n-type and p-type quasi-neutral regions.
As a negative voltage is applied, the potential across the semiconductor increases and so does the depletion layer width. As a positive voltage is applied, the potential across the semiconductor decreases and with it the depletion layer width. The total potential across the semiconductor equals the built-in potential minus the applied voltage
The different between Forward bias and Reversed bias are Forward bias, the potential energy across the junction is reduced in this case, an appreciable number of electrons now have sufficient energy to cross the junction. There is a net diffusion of electrons across the barrier from the n side to the p side, producing net electrons current from p to n. For Reversed bias, the electrons in the n material (majority carriers) attempt to diffuse toward the p-type material (region of lower concentration). However, there is a potential energy barrier there.
forward bias:potential hill(band bending is lowered.many majority carriers can accross the hill to diffuse to p-side.The voltage supply must be positive value because of Va value is +ve. Vj=Vbi-(+Va) =Vbi-Va
reversed bias: potential hill(band bending) is increased.if minority carriers wander to the depletion region,it is swept over to n-side.The voltage supply must be in -ve value because of value of Vj is +ve. Vj=Vbi-(-Va) =Vbi+Va
Different between FB and RB can see at their depletion width and the peak electric field at the junction will decreases under FB while they increase under RB. For FB, Vtot = Vbi - Vf RB, Vtot = Vbi + Vr
The difference between forward bias and reverse bias; 1)The essential difference between forward-bias and reverse-bias is the polarity of the voltage dropped across the diode 2)When the diode is forward-biased and conducting current, there is a small voltage dropped across it, leaving most of the battery voltage dropped across the lamp. When the battery's polarity is reversed and the diode becomes reverse-biased, it drops all of the battery's voltage and leaves none for the lamp
Forward bias is the potential energy across the junction is reduced and many majority carriers can accross the hill to diffuse to p-side.Positive voltage is applied.
Reverse bias is negative voltage is applied.Potential hill is increased and the electrons in the n material attempt to diffuse toward the p-type material
Forward bias is the potential energy across the junction is reduced and many majority carriers can accross the hill to diffuse to p-side.Positive voltage is applied.
Reverse bias is negative voltage is applied.Potential hill is increased and the electrons in the n material attempt to diffuse toward the p-type material
zuraini muhammad @ mohamed shaari 2007121763 eeb4f
forward bias is potential across juntion decreases Vj=Vbi-Va.Va is voltage applied.In forward bias voltage applied is positive.depletion region layer width decreases
reverse bias is potential across juntion increases Vj=Vbi-(-Va).Va is voltage applied.In forward bias voltage applied is negative.depletion region layer width increases
the difference between forward bias and reverse bias is the polarity of the voltage dropped across the diode.
for forward bias is the potential energy across the junction is reduced and many majority carriers can accross the hill to diffuse to p-side.Positive voltage is applied.
for reverse bias is negative voltage is applied.Potential hill is increased and the electrons in the n material attempt to diffuse toward the p-type material
Forward bias is potential across junction decreases Vtotal=Vbi-Va .Va is positive.Depletion layer width decreases, providing less ionized donors and acceptors as expected from the decrease in potential barrier and thus decrease in electric field.
Reverse bias is potential across junction increases Vtotal=Vbi-Va but Va is negative.Depletion layer width increases, providing more ionized donors and acceptors as expected from the increase inpotential barrier and thus increase in electric field.
So, Total space charge in respective regions reduces with forward bias and increases with reverse bias.
/*MOHD UBAIDILLAH BIN SHAMSUDIN*/ /*2007126591*/ /*EEB4E*/
The different between forward bias and reverse bias is forward biased,the polarity voltage applied(Va) to the np s/c is same as np side polarity. The voltage supply must be positive value because of Va value is +ve: Vj = Vbi-(+Va) = Vbi-Va While at reversed bias is negative voltage is applied.Potential hill is increased and the electrons in the n material attempt to diffuse toward the p-type material. The polarity voltage applied(Va) to the np s/c is opposite to the polarity np s/c. When Va is applied Vj is increases. Then the equation is show below: Vj = Vbi-(-Va) = Vbi + Va
20 comments:
difference between forward bias and reverse bias:
forward bias:at forward biased,the polarity voltage applied(Va) to the np s/c is same as np side polarity as example:http://en.wikipedia.org/wiki/Image:PN_Junction_in_Forward_Bias.png
at forward biased,the junction voltage(Vj) is smaller than zero bias(Vbi) by
Vj=Vbi-Va,forward bias Va is (+).
reversed bias:at reversed bias,the polarity voltage applied(Va) to the np s/c is opposite to the polarity np s/c as example:http://en.wikipedia.org/wiki/Image:PN_Junction_in_Reverse_Bias.png
at reversed bias,the junction voltage(Vj) is higher than built-in voltage(Vbi) by
Vj=Vbi-Va,reversed bias Va is (-) so,Vj=Vbi+Va.
~~2007126643~~
eeb4f
A p-n diode with an applied bias voltage, Va. A forward bias corresponds to applying a positive voltage to the anode (the p-type region) relative to the cathode (the n-type region). A reverse bias corresponds to a negative voltage applied to the cathode. The applied voltage is proportional to the difference between the Fermi energy in the n-type and p-type quasi-neutral regions.
As a negative voltage is applied, the potential across the semiconductor increases and so does the depletion layer width. As a positive voltage is applied, the potential across the semiconductor decreases and with it the depletion layer width. The total potential across the semiconductor equals the built-in potential minus the applied voltage
*2007292004*
*EEB4E*
The different between Forward bias and Reversed bias are Forward bias, the potential energy across the junction is reduced in this case, an appreciable number of electrons now have sufficient energy to cross the junction. There is a net diffusion of electrons across the barrier from the n side to the p side, producing net electrons current from p to n. For Reversed bias, the electrons in the n material (majority carriers) attempt to diffuse toward the p-type material (region of lower concentration). However, there is a potential energy barrier there.
Dayang Maslin Hj Bukari
2007270442
forward bias:potential hill(band bending is lowered.many majority carriers can accross the hill to diffuse to p-side.The voltage supply must be positive value because of Va value is +ve.
Vj=Vbi-(+Va)
=Vbi-Va
reversed bias: potential hill(band bending) is increased.if minority carriers wander to the depletion region,it is swept over to n-side.The voltage supply must be in -ve value because of value of Vj is +ve.
Vj=Vbi-(-Va)
=Vbi+Va
Different between FB and RB can see at their depletion width and the peak electric field at the junction will decreases under FB while they increase under RB.
For FB, Vtot = Vbi - Vf
RB, Vtot = Vbi + Vr
The difference between forward bias and reverse bias;
1)The essential difference between forward-bias and reverse-bias is the polarity of the voltage dropped across the diode
2)When the diode is forward-biased and conducting current, there is a small voltage dropped across it, leaving most of the battery voltage dropped across the lamp. When the battery's polarity is reversed and the diode becomes reverse-biased, it drops all of the battery's voltage and leaves none for the lamp
mohd ikhwan
2007290828
eeb4e
Forward bias is the potential energy across the junction is reduced and many majority carriers can accross the hill to diffuse to p-side.Positive voltage is applied.
Reverse bias is negative voltage is applied.Potential hill is increased and the electrons in the n material attempt to diffuse toward the p-type material
Forward bias is the potential energy across the junction is reduced and many majority carriers can accross the hill to diffuse to p-side.Positive voltage is applied.
Reverse bias is negative voltage is applied.Potential hill is increased and the electrons in the n material attempt to diffuse toward the p-type material
zuraini muhammad @ mohamed shaari
2007121763
eeb4f
Difference between forward bias and reverse bias:
forward bias is potential across juntion decreases Vj=Vbi-Va.Va is voltage applied.In forward bias voltage applied is positive.depletion region layer width decreases
reverse bias is potential across juntion increases Vj=Vbi-(-Va).Va is voltage applied.In forward bias voltage applied is negative.depletion region layer width increases
2007121889
different between this bias is sign of Va.forwad bias is (+Va) and reverse bias is (-Va).the total equation for junction voltage is Vj=Vbi - (Va).
the difference between forward bias and reverse bias is the polarity of the voltage dropped across the diode.
for forward bias is the potential energy across the junction is reduced and many majority carriers can accross the hill to diffuse to p-side.Positive voltage is applied.
for reverse bias is negative voltage is applied.Potential hill is increased and the electrons in the n material attempt to diffuse toward the p-type material
the difference forward bias and reverse bias are:
forward bias: value for applied voltage,Va is positive value.
reverse bias : value for applied voltage,Va is negative value.
from equation Vj=Vbi-Va:
if reverse bias,value for junction voltage,Vj will decrease because Vj=Vbi-(+Va)
if forward bias,Vj will increase because Vj=Vbi-(-Va).
the difference forward bias and reverse bias are:
forward bias: value for applied voltage,Va is positive value.
reverse bias : value for applied voltage,Va is negative value.
from equation Vj=Vbi-Va:
if reverse bias,value for junction voltage,Vj will decrease because Vj=Vbi-(+Va)
if forward bias,Vj will increase because Vj=Vbi-(-Va).
shahizawanis bt shamshuri
2006687187
eeb4e
The difference between forward bias and reverse bias is:
a)forward bias: Va is positive value.Many majority carriers can accross the hill to diffuse to p-side. potential energy across the junction is reduced
b)reverse bias Va is negative value. the electrons in the n material attempt to diffuse toward the p-type material.potential hill is increased.
from equation Vj=Vbi -Va
in reverse bias: Vj=Vbi-(+Va)
in forward bias: Vj=Vbi-(-Va).
>MUHAMAD IZUAN BIN IBRAHIM<
>2007126589<
>EEB4E<
Forward bias is potential across junction decreases Vtotal=Vbi-Va .Va is
positive.Depletion layer width decreases, providing less ionized donors and acceptors as expected from the decrease in potential barrier and thus decrease in electric field.
Reverse bias is potential across junction increases Vtotal=Vbi-Va but Va is negative.Depletion layer width increases, providing more ionized donors and acceptors as expected from the increase inpotential barrier and thus increase in electric field.
So, Total space charge in respective regions reduces with forward bias and increases with reverse bias.
/*MOHD UBAIDILLAH BIN SHAMSUDIN*/
/*2007126591*/
/*EEB4E*/
The different between forward bias and reverse bias is forward biased,the polarity voltage applied(Va) to the np s/c is same as np side polarity. The voltage supply must be positive value because of Va value is +ve:
Vj = Vbi-(+Va)
= Vbi-Va
While at reversed bias is negative voltage is applied.Potential hill is increased and the electrons in the n material attempt to diffuse toward the p-type material. The polarity voltage applied(Va) to the np s/c is opposite to the polarity np s/c. When Va is applied Vj is increases. Then the equation is show below:
Vj = Vbi-(-Va)
= Vbi + Va
mohd khairul anuar bin awang
2007121771
eeb4e
For forward bias the value for applied voltage,Va is positive value while for reverse bias value for applied voltage,Va is negative value.
NUR ATHIRA BINTI MOHAMAD
2006687745
EEB4E
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