Silicon-based solar cells Characteristics and production processes ...

Silicon-based solar cells – characteristics and production processes
As it can be concluded from the comparative analysis of the photovoltaic
conversion efficiency E ff of cells and PV modules, the efficiency of the latter is always
lower than that of the cells, due to the proportion of the total surface of the cells to
the surface of the module, which is always lower than unity, and also, due to the
slight reflection of light from the glass panels which protect the module and which
are simultaneously its carrying material, as well as from the foils hermetizing the cells
in the module.
.
34%
8% 5%
3% 1%
49%
mc Si
Cz-Si
CdTe
a-Si
R-Si
CIGS
Fig. 2. Proportional share of a given solar cell type in the total solar cell production of global
photovoltaics in 2008 [2].
The comparison of the proportional share of particular types of solar cells
manufactured in 2008 unequivocally points to the domination of the crystalline
silicon-based cells and a significant share of the thin-layer cells type CdTe and CIGS.
In 2009, the share of the thin-layer cells increased up to nearly 19 %, due to the
increase in the CdTe cell production by the American company, First Solar. The issue
necessary to resolve is the five-percent share of the a-Si amorphous silicon-based
cells. This value partially refers to the HIT –type cells produced by the Japanese
company, Sanyo, whose base material is mono-crystalline silicon, and the emitter is
formed by an amorphous silicon layer.
The domination of the Cz-Si and mc-Si cells results from several facts, which can
be presented in the following points:
• A very good knowledge of the material and a developed research and
diagnostic, Si-oriented, base, also resulting from the previous achievements of
the electronic industry.
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