Question 1

1x108

1x107

1x106

1x105

1x104

1x103.

Si

².

0.2 0.4

a-SH

Ge

GaAs

InP

1

InoGao 3AS06P036

1.0

0.9

1.2

0.8

0.6 0.8

(a) In the context of photodetectors and the interaction of light with semiconductor

materials, what property exhibits the behaviour represented in the figure above? Label

all the axes (including the units, and including both the upper and lower x axes). Define

the quantity on the y axis and discuss the difference (if any) between its properties in

direct and indirect band gap materials.

[4 marks]

Ino5G047As

1.4

0.7

1.6

1.8