Electronic Structure of Solids

Question 1

broadening

Answer 1

due to small dE between BMO and ABMO when considering large no of orbitals

Question 2

conduction band

Answer 2

broadening of ABMO

Question 3

valence band

Answer 3

broadening of BMO

Question 4

metal

Answer 4

overlapping valence and conduction bands

Question 5

semiconductor

Answer 5

small gap between valence and conduction, crossed thermally

Question 6

insulator

Answer 6

large gap between valence and conduction

Question 7

Evac

Answer 7

vacuum level, zero of energy, electrons above this are free of material

Question 8

Φ

Answer 8

work function, energy needed to remove e- from solid

Question 9

Ef

Answer 9

fermi energy, highest electronic energy state in a metal

Question 10

Eg

Answer 10

band gap, gap between valence and conduction bands

Question 11

why do different surfaces of same substrate have different Φ

Answer 11

to generate surface have decay of some e density at the surface due to quantum mechanical tunnellign, potential well containing e- isnt as deep, gives dipolar region as surface has lost an e-

Question 12

electropositive adsorbers

Answer 12

valence level above Ef, e- transfer from adsorbate to surface generating +ve charge on adsorbate

Question 13

electronegative adsorbers

Answer 13

valence level below Ef, e- transfer from surface to adsorbate generating -ve charge on surface