knjiga solarna energija dobra

REQUIREMENTS OF SILICON FOR CRYSTALLINE SOLAR CELLS 191
Temperature
[°C]
10 18 1400 1300 12001100 1000 900 800 700 600 500
10 −5
10 17
Co
10 −6
10 16
Mn
Cu
10 −7
Concentration
[1/cm 3 ]
10 15
Ti
Ni
10 −8
Concentration
10 14 10 −10
Cr
10 −9
10 13
Fe
Co
10 12
0.6
0.7
0.8 0.9
1000/T
[1/K 1 ]
1.0 1.1 1.2 1.3
Figure 5.10 Solid solubility of 3d transition elements in silicon. Sc is still missing, but is assumed
to be a little below the values of Ti. Adapted from J. Appl. Phys. Weber E, A30, 1–22 1983, ©
Springer-Verlag GmbH & Co. KG. The values for Ti are taken from [37]
composition of several transition-metal precipitates in silicon identify crystalline silicides,
FeSi 2, CoSi 2, NiSi 2, as compounds that influence the minority-carrier diffusion length.
The morphology and density depend upon temperature and time at temperature. Elements
having a high diffusivity like Ni and Cu precipitate easily. This reduces the number of
atoms in solid solution and may therefore change the electric properties. Kittler and