Physics of Semiconductor Devices by Massimo Rudan

Author:Massimo Rudan
Language: eng
Format: epub, pdf
Publisher: Springer International Publishing, Cham

(18.63)

whence

(18.64)

Fig. 18.14Density of states in an n-doped semiconductor, where the high concentration of the dopant produces the band-gap narrowing. The gap’s extension is arbitrary and does not refer to any specific material

To calculate the carrier concentrations when band-gap narrowing is present, one must replace E C with in the second relation of (18.56), and E V with in the second relation of (18.57), to find

(18.65)

(18.66)

Band-gap narrowing makes ξ e , ξ h to increase with respect to the moderately doped case; as a consequence, the equilibrium carrier concentrations n and p are larger as well. As mentioned in Sect. 18.3, band gap is measured by either electrical or optical methods. The results of gap’s measurements, that show that E G decreases when the dopant concentration exceeds some limiting value N r , are usually rendered in compact form by means of interpolating expressions, an example of which is, for silicon [125], [126],

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.