textbook readings MSE Chapter 18 equations Basic R IR V Electrical properties I physical quantities PI 5 E E p current density GE A GE J drift velocity Vd Of I és in unit volume heard Neff neAV I election mobility applied electric Me Va ME to drift velocity relates off field Me Me If me Men let f Mene pure Electronic band model single atom discrete energy levels g Is multiple atoms aggregate as in a solid lattice of neighboring atoms overlap energy levels This creates energy bands When higher at smaller interatomic spacings resemble the to start they As interatomic spacing discrete energy levels of isolated atoms Overlap is of states orbitals that é pairs P fimpy N contributing orbitals N is determined by contribute eg sp2 orbitals 3 as s Pip N orbitalsstates be will there If N atoms mix orbitals in the s band atom etc 3N in the p band as there 3 p in each possible band structures E conduction band YE interatomic spacing overlapping valence conduction bands May fill up anyof reselevels 71ps evel 1 1 17 1 2711 is.ee Good conductors event Energy gapbetween valence conduction bands completely filled as it can easily conduction band go to eg Mg 352 E q is b stiff it is not fun e space to get excited within the band Then conductor egCu BUT if valence band is full it is either an insulator on or semiconductor based band gap semiconductor EF dingtÑ Int hÉ h that in examples some E ang fnhL mg C vs.si whldn't C bandgap be lover AH depends on interatomic spacing Semiconductor Insulator actual crystal structure diamond re graphite In conductor defects substitutions vacancies by thermally vibrating lattice As T occurs due to resistance cone of intrinsic semiconductors P Pt y pit Pa etc atoms as insulators interstitials of resistance conductors 5 scattering é scatterers as by carrier cone e excitation Includenotes on Mathiesen's rule I Acceptors donor states of n p type semiconductors_ Understanding why Vy is switched for n type p FB B p n type_ type AFB I E D It IE moving e falls bound lattice into'Ñe is obscured so what exists as Huffed an_ charge is the
