https://doi.org/10.1051/epjap/2010110
Scribing of a-Si thin-film solar cells with picosecond laser
Laboratory for Applied Research, Center for Physical Science and Technology,
Savanoriu Ave. 231, 02300 Vilnius, Lithuania
Corresponding author: graciukaitis@ar.fi.lt
Received:
12
October
2009
Accepted:
11
June
2010
Published online:
2
September
2010
The thin-film technology is the most promising technology
to achieve a significant cost reduction in solar electricity. Laser scribing
is an important step to preserve high efficiency of photovoltaic devices on
large areas. The high-repetition-rate laser with the pulse duration of 10 ps
was applied in selective ablation of multilayer thin-film a-Si solar cells
deposited on flexible and rigid substrates. Two types of solar cells with
flexible and rigid substrates have been investigated. The first type of
solar cells was made of 400 nm a-Si layer coated on both sides with 2 
m transparent ZnO:Al contact layers deposited by CVD technique on the glass
plate. The second type of solar cells was made of a flexible polyimide
substrate coated with the Al back-contact, a-Si light absorbing layer and
the ITO top-contact. Selection of the right laser wavelength is important to
keep the energy coupling in a well defined volume at the interlayer
interface. Well-defined shapes of scribes were produced by laser ablation
through layers of the solar cell on the glass substrate. Localization of the
coupled energy at the inner interface led to the “lift-off” type process
rather than evaporation of the top ITO layer when the 355 nm radiation was
applied. All laser scribes did not indicate any material melting or other
thermal damage caused by laser irradiation. Ultra-short picosecond pulses
ensured the high energy input rate into absorbing material therefore peeling
of the layers had no influence on the remaining material.
© EDP Sciences, 2010
