knjiga solarna energija dobra

340 THIN-FILM SILICON SOLAR CELLS
Type I region Type II or IV region
N
N
P
P
P-N junction depletion
regions; their widths are
different in Type I and
Type II/IV regions
Possible depletion region
in high/low junction at the
Type I /Type III interface
Type I, II, or IV region Type III region Type I, II, or IV region
(a)
N
N
J 1
J 2
(b)
P
J 1
P
Depletion region(s) at the interface
P-N junction depletion region(s)
Figure 8.23 The proposed model of different regions in an n-p junction built on imperfect material.
(a) The model of Type I, II, and IV regions, and the relationship among them inside a device.
(b) The junction at the interface of Type I, II, IV region, and Type III region. J 1 and J 2 are current
flows discussed in Reference [19]. The distribution of carriers inside the Type III region is not
considered
J SC
[mA/cm 2 ]
17.0
16.5
16.0
15.5
15.0
14.5
14.0
13.5
0.1 1 10
Grain size
[µm]
100
V OC
[V]
0.60
0.55
0.50
0.45
0.40
0.35
0.30
0.25
0.1 1 10
Grain size
[µm]
100
(a)
(b)
Figure 8.24 Calculated dependence of (a) J SC ;and(b)V OC on the grain size of the 10-µm-thick
cell for two values of interface recombination velocity, 100 cm/s (solid lines) and 1000 cm/s (dotted
lines)