semiconductor question.

[sagar474]

if a sample of germanium and a sample of silicon have same impurity density and are kept at room temperature. what is the polarity of voltage that was developed across the bar.

 

[edwinc]

What is the question?

 

[sagar474]

What is the question?

I'm sorry I edited this question.

 

[Raza]

Hi,
you are completely mistaken about Silicone and Germanium. There is never any voltage production on these materials by themselves.

 

[yadavvlsi]

If it is piece of germanium and silicon, no voltage is developed across it. If you are asking about built-in-potential of germanium and silicon diodes. For germanium it is 0.3V and for silicon it is 0.7V. Built-in-potential changes with doping.

 

[Raza]

There is no built in potential in any diode. The Germanium PN juction DROPS 0.3 volts across itself when forward biased and 0.7 volt dropped across Silicone PN junction when biased forward.

 

[yadavvlsi]

There is no built in potential in any diode. The Germanium PN juction DROPS 0.3 volts across itself when forward biased and 0.7 volt dropped across Silicone PN junction when biased forward.

There is built in potential in every diode but you can't measure it using voltmeter.
**broken link removed**
**broken link removed**
https://www.edaboard.com/threads/135227/

 

[Raza]

There is built in potential in every diode but you can't measure it using voltmeter.
p-n Junctions
Built-in potential of a p-n junction
Built in potential for PN junction diodes

This is caused by the temperature and is called the Built-in Potential;


**broken link removed**

Look at the questions and relative answers of your reference:

 

[yadavvlsi]

This is caused by the temperature and is called the Built-in Potential;

Built in potential is given by

and temperature is one of its component. Mainly it depends on intrinsic carrier concentration and doping levels.