epdf.pub_nanotechnology-and-nanoelectronics-materials-devic

3.2 Characterization of Nanodefects in Crystals 21
bination statistics:
q n
g i
(3.1)
2
G
where n i is the intrinsic charge carrier density and G the generation lifetime
1 vth
NT
ET
E
G
i
cosh
k T
(3.2)
(: capture cross section, E T : energy level, N T : density of traps, E i : Fermi level,
and v th : thermal velocity).
We can easily show that a plot of
d
C
dt
C
ox
hf
2
(the integrated generation rate G tot , i.e., the generation current density) vs.
Fig. 3.6 Photoluminescence of a nanostructured surface of Si, (a) as measured,
(b) after subtracting the background [23]