![Solid State Physics artwork](https://is1-ssl.mzstatic.com/image/thumb/Podcasts6/v4/50/1b/7a/501b7a7c-424b-b88d-73d6-620930028d00/mza_5180078778862395739.jpg/100x100bb.jpg)
Lecture 12: Semiconductors
Solid State Physics
English - February 23, 2006 14:24Science Education Courses solid state physics condensed matter science fun materials Homepage Download Apple Podcasts Google Podcasts Overcast Castro Pocket Casts RSS feed
Today is all about semiconductors. We talk about how to dope them. Donor atoms "donate" electrons into the conduction band, giving n-type semiconductors, with mostly electrons carrying current. Acceptor atoms "accept" atoms from the valence band, leaveng holes there. These are p-type semiconductors. We also discuss the effective mass of the electrons and holes in a band, and how to calculate it. (It changes based on the curvature of the band -- that's right, the electron might act more or less free inside the material, but act as though it has a different mass.) We look at the physics of how the dopant atoms "ionize" to contribute carriers to the semiconductor.
There's also a way to measure whether the semiconductor's main carriers are holes or electrons, using the Hall Effect.
Lecture Audio