Environmental Engineering Reference
In-Depth Information
Figure 6.3
An energy band diagram of the tandem solar cell shown in
Fig. 6.2, containing three p-i-n diodes.
Figure 6.4
A schematic diagram of a tandem solar cell fabricated by
connecting a large number of cells in parallel. The bandgaps of material
layers gradually reduce (
E
g1
>
E
g2
>...>
E
g7
>
E
g8
), and the conduction
typevariesfromn
+
top
+
fromthefronttothebackofthesolarcell.Seealso
Colour Insert.
of such a device, respectively. In this case, the material changes its
conduction type from n
+
to p
+
through a series of layers consisting
of n
+
,n,n
−
,i,p
−
,pandp
+
. In this notation, n
+
,n,n
−
,andidenote
heavily n-doped, moderately n-doped, low n-doped, and intrinsic
