A-MT-Ch03-Intrinsic-&-extrinsic-sem iconductors

O bothh haveoneele ectronboundbycoulom mbicinteract

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Unformatted text preview: kT = 26 6 meV o Since Ed and kT ar re similar full ionizatio on of donors s n ND N D Chapter 3 – page 3 Note similarit N ty between d donors and the hydroge en atom. o Both h have one ele ectron bound by coulom mbic interact tion o Hydro ogen atom m model for do onors o Modif fication of hy ydrogen ato om model by y * 1) Effective m mass me me 2) Dielectric constant 0 r0 o Hydro ogenic impur rities closely y follow the h tom model (Bohr’s mode el) hydrogen at emiconducto ors p‐type se Se econd thoug ght experiment o Remo ove one Si atom in a Si cr rystal and re eplace it a bo oron (B) atom m o B is gr roup‐III elem ment Chemical bon nd model B wants to capture (accept) an electron in o order to ach hieve an ine ert‐gas elec ctron‐ co onfiguration n Band model f for acceptors Acceptor acce A epts an electron from th he valence b band Io onization en nergy or acti ivation energy o Ea ≈ 5‐50 meV o At T = 300 K: Ther rmal energy y = kT = 26 6 meV o Since Ea and kT ar re similar full ionizatio on of accept tors p NA N A Chapter 3 – page 4 Compensated semiconductors When a semiconductor is doped simultaneously with donors and acceptors, it is called a compensated semiconductor o Example: Si doped simultaneously with P and B o co...
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This note was uploaded on 04/03/2014 for the course ECSE 2210 taught by Professor Huang during the Fall '12 term at Rensselaer Polytechnic Institute.

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