Reverse saturation current in si diode

[aghahusain]

What will be the effect of temperature on the diode during reverse bias condition?

 

[Ratch]

aghahusain,

What type of diode? PN junction, Gunn diode, IMPATT diode, laser diode, photo diode, PIN diode, Schottky barrier diode, step recovery diode, tunnel diode, varacter diode, Zener diode, or LED, which?

Ratch

 

[godfreyl]

I'm not sure what you mean by "Reverse saturation current". When a normal diode such as 1n4148 is reverse biased, it is switched off and only a small leakage current flows. This reverse current increases at higher temperatures.



edit: Nevermind, I looked up Reverse saturation current

 

[aghahusain]

thanks Ratch.

Actually i m looking for PN Junction diode in detail. wehave found that Reverse saturation current is quite low in Reverse bias and it increases with increse in temp. i wanna know how.

 

[jeffrey samuel]

in the case of PN diode the reverse saturation current increases about 70% for every 10 degree rise in temperature

 

[Ratch]

aghahusain,

Actually i m looking for PN Junction diode in detail. wehave found that Reverse saturation current is quite low in Reverse bias and it increases with increse in temp. i wanna know how.

When you ask "how", do you mean how much? Look at Schockley's diode equation and calculate the current at say, 1°, 5°, and 10°, and see what the difference is.

Ratch

 

[jeffrey samuel]

there are several thing to know for purely temperature is not the only criteria as the mobility of the carriers are varied with increase in temperature

 

[peeyushsigma]

reverse saturation current in p-n junction diode will be just double in magnitude for every 10°C rise in temperature.....
"it is found experimentally"

 

[jeffrey samuel]

reverse saturation current in p-n junction diode will be just double in magnitude for every 10°C rise in temperature.....
"it is found experimentally"

i dono why but theoretically it has to increase only 70% of the actual value check the relationship of temperature and sat. current for more info

 

[yadhu]

reverse saturation current is due to minority carriers in diode, as temperature increases no, of minority carriers will increase hence saturation current increases

 

[jeffrey samuel]

reverse saturation current is due to minority carriers in diode, as temperature increases no, of minority carriers will increase hence saturation current increases

this is true cos of the more energy gained by the minority carriers from what is called thermal voltage (Vt) by the heat energy dissipated at the junction

higher heat=>> high voltage =>> more minority carriers =>> higher reverse sat current

 

[yogece]

if you want measure temperature you can use a PN junction diode either in the forward biased condition or in the reversed biased condition in the forward condition the voltage drop across diode would be reduced by 2.5mV/oC in the reversed condition the reverse current thro' the diode would increase

 

[jeffrey samuel]

if you want measure temperature you can use a PN junction diode either in the forward biased condition or in the reversed biased condition in the forward condition the voltage drop across diode would be reduced by 2.5mV/oC in the reversed condition the reverse current thro' the diode would increase

the fact also lies in what ckt the diode is used causes the effect

if the ckt dissipates a lot of heat then it is better to use some coolers and stuff to keep the internal temperature of diodes down

also now a days heat sink are pretty popular they can also be used to reduce the heat liberated