Added: May 5, 2010
From: TutorVista
Duration: 5:42
Check us out at http://www.tutorvista.com/content/physics/physics-iv/semiconductor-devices/intrinsic-semiconductors.php Intrinsic Semiconductor An intrinsic semiconductor is one, which is pure enough that impurities do not appreciably affect its electrical behavior. In this case, all carriers are created due to thermally or optically excited electrons from the full valence band into the empty conduction band. Thus equal numbers of electrons and holes are present in an intrinsic semiconductor. Electrons and holes flow in opposite directions in an electric field, though they contribute to current in the same direction since they are oppositely charged. Hole current and electron current are not necessarily equal in an intrinsic semiconductor, however, because electrons and holes have different effective masses (crystalline analogues to free inertial masses). The concentration of carriers is strongly dependent on the temperature. At low temperatures, the valence band is completely full making the material an insulator. Increasing the temperature leads to an increase in the number of carriers and a corresponding increase in conductivity. This characteristic shown by intrinsic semiconductor is different from the behavior of most metals, which tend to become less conductive at higher temperatures due to increased phonon scattering. An extrinsic semiconductor is one that has been doped with impurities to modify the number and type of free charge carriers. Please like our facebook page http://www.facebook.com/tutorvista
Channel: Education
Rating: 4.9444447' max='5' min='1' numRaters='72' rel='http://schemas.google.com/g/2005#overall ( ratings) Views: 25201 Comments: 14
sameer ahmed Says:
Mar 3, 2011 - thnx...it was usefull..
venkata ramana Jeedi Says:
Mar 16, 2011 - i like this
vamshi ranga Says:
Nov 2, 2011 - nicely explained..
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Tommybotham Says:
Mar 27, 2012 - Excellent account.
Sunnyman2012 Says:
Oct 25, 2012 - Wow, it just eliminated ages of doubts, thank you!!!
utkarsh dua Says:
Jan 16, 2013 - good work
tsunami3456789 Says:
Mar 8, 2013 - 100% helpful. Great job..,,
Kaisar Ali Says:
Mar 24, 2013 - Solid State Electronic Devices is a garbage book. This video give me the knowledge in 5 minutes that I couldn't get from this trashy book in 5 hours of reading
artymex Says:
Mar 25, 2013 - Even if some books are better than others, is doesn't mean that it must be considered garbage. Whit this kind of comments you show that you hate TO STUDY.
artymex Says:
Mar 25, 2013 - If you're going to show the behavior of intrinsic silicon, is becomes a waste of time to show also the behavior of pure germanium, as both behaves in the same way. On the other hand, even if the explanation of an extrinsic semiconductor is well conducted, it would be better to use the case of silicon instead of germanium (for technological reasons).
Kaisar Ali Says:
Apr 2, 2013 - You comment wasn't needed and don't try to prove that you are a nerd sitting in mama's basement learning all about solid state. Just keep your mouth shut and move on. Your opinion is disregarded fool.
artymex Says:
Apr 4, 2013 - When someone finds nothing but insult to respond... EDUCATION is THE ANSWER.
MrAaabbasi Says:
Feb 5, 2011 - it was supppperb!thnx