SEMICONDUCTOR DEVICE PHYSICS AND DESIGN

54 CHAPTER 2. ELECTRONIC LEVELS IN SEMICONDUCTORS

ELEMENT VALENCE DENSITY CONDUCTION

(gm/cm^3 ) ELECTRON DENSITY

(10^22 cm–3)

Al 3 2.7 18.1

Ag 1 10.5 5.86

Au 1 19.3 5.90

Na 1 0.97 2.65

Fe 2 7.86 17.0

Zn 2 7.14 13.2

Mg 2 1.74 8.61

Ca 2 1.54 4.61

Cu 1 8.96 8.47

Cs 1 1.9 0.91

Sn 4 7.3 14.8

Table 2.2: Properties of some metals. In the case of elements that display several values of
chemical valence, one of the values has been chosen arbitrarily.