Temperature Dependence of Semiconductor Conductivity
Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
projectsofme
Active In SP
**

Posts: 1,124
Joined: Jun 2010
#1
28-09-2010, 05:18 PM



.doc   tech_LN08_semiconductorresistance.doc (Size: 139.5 KB / Downloads: 214)
Learning Objectives

After successfully completing this laboratory workshop, including the assigned reading, the lab blue sheets, the lab quizzes, and any required reports, the student will be able to:
• Describe how semiconductor conductivity varies with temperature.
• Draw a band diagram for a semiconductor.
• Describe how doping a semiconductor improves conductivity.
• Define n-type and p-type semiconductors.
• Relate the bonding type to the materials’ electrical properties.
• Determine the band gap energy for a semiconductor from measured data in the intrinsic region.
• Distinguish between intrinsic and extrinsic temperature regimes and identify the applicable temperature range from an examination of measured data.
• Express the mathematical relationships between carrier concentration and temperature in the intrinsic, extrinsic and ionization regimes.
• Express the functional relationship between mobility and temperature in the intrinsic, extrinsic and ionization regimes.

Theory
Band Structure of a Semiconductor

The band structure of semiconductors is such that the outermost band of electrons, the valence band, is completely full. If a voltage is applied, there is no conduction of electrons because there are no empty spaces to allow the electrons to move around. In order for conduction to occur, electrons must be excited to the next highest band, known as the conduction band. The conduction band is normally empty but is separated from the valence band by only a small amount of energy. Valence electrons can surmount this barrier by absorbing a small amount of energy from heat or light. This then creates a free electron in the conduction band and a hole (missing electron) in the valence band,
Doping (replacing Si atoms with atoms of another element) is frequently used instead of temperature to control conductivity. Doping can be localized to certain areas whereas the affect of temperature is a less localized influence. If Si is replaced by elements from Column V of the periodic table such as phosphorous, there will be one extra electron in the valence band, This electron is easily broken loose to create a free electron. Silicon doped with Column V elements in known as p-type and the dopants are called donors. Replacing Si with an element from Column III (such as boron) creates a hole in the valence band. The silicon is known as n-type and the dopants are called acceptors.
Reply

Important Note..!

If you are not satisfied with above reply ,..Please

ASK HERE

So that we will collect data for you and will made reply to the request....OR try below "QUICK REPLY" box to add a reply to this page

Quick Reply
Message
Type your reply to this message here.


Image Verification
Please enter the text contained within the image into the text box below it. This process is used to prevent automated spam bots.
Image Verification
(case insensitive)

Possibly Related Threads...
Thread Author Replies Views Last Post
  A SEMINAR REPORT ON APPLICATION OF POWER SEMICONDUCTOR DEVICES & ITS IMPLEMENTATION study tips 0 432 16-02-2013, 03:07 PM
Last Post: study tips
  PID Temperature Controller ppt study tips 0 505 16-02-2013, 10:55 AM
Last Post: study tips
  PRPPERTIES OF SEMICONDUCTOR PPT project girl 0 339 19-01-2013, 02:55 PM
Last Post: project girl
  Design of An Embedded System For Monitoring and Controlling Temperature and Light project girl 0 441 24-12-2012, 04:13 PM
Last Post: project girl
  A Presentation on SEMICONDUCTOR PPT project girl 0 507 10-12-2012, 03:07 PM
Last Post: project girl
  A Presentation on SEMICONDUCTOR PPT project girl 0 351 10-12-2012, 03:06 PM
Last Post: project girl
  The Metal–Oxide–Semiconductor Field-Effect Transistor (MOSFET) project girl 0 450 06-12-2012, 04:29 PM
Last Post: project girl
  EXTRINSIC SEMICONDUCTOR PPT project girl 0 578 05-12-2012, 01:31 PM
Last Post: project girl
  Temperature Sensor - The LM35 report project girl 0 451 04-12-2012, 04:34 PM
Last Post: project girl
  A SEMINAR ON SEMICONDUCTOR PPT project girl 0 377 23-11-2012, 11:46 AM
Last Post: project girl