Scientists
at INM-Leibniz Institute for New Materials in Saarbrücken, Germany, has
developed a barrier layer that separates the metal carrier from the
absorber film and thus increases the efficiency of metal-based CIGS
solar cells. The INM program division “Optical Materials” has for the
first time presented this development in the German Pavilion at the
international trade fair “nano tech 2011? and also nationwide at the
Hannover Messe 2011.
Corrosion
and poor isolation between substrate and carrier material cause a lower
efficiency for CIGS solar cells apart from other influences. Solar
cells consist of copper (C), indium (I), gallium (G), and sulphur (S).
Glass as carrier material and the low efficiency prevent the flexible
application of these future solar cells in the automotive industry, for
example.
The
developed layer is glass-like. “It works as iron diffusion barrier and
thus prevents corrosion and oxidation of the carrier”, explains Peter
William de Oliveira, head of the program division. “At the same time,
the barrier works as insulating layer and reduces unintentional
electrical currents from the absorber to the carrier”, says Oliveira.
Both functions increase the efficiency of metal-based CIGS solar cells
by up to 13 percent.
The
glass-like diffusion barrier is applied on the metal carrier by means
of the sol-gel process. It is transparent and flexible and has a
thickness of only a few micrometers. The INM scientists developed both
the layer and up-scaled process. By means of dip coating and slot
coating they produced foils in a DIN A3 size. The traditional
roll-to-roll printing process allows the production of continuous
layered foils up to a length of 50 meters and a width of about half a
meter.
These
and other applications are exhibited by INM at the international trade
fair “nano tech 2011?. Included are coatings with special properties, as
for example transparent conductivity, antiadhesive, scratch-proof,
antireflective or self-cleaning function, or layers for friction
reduction or corrosion protection. Multifunctional coatings, which
combine several of these properties, also belong to the INM research
portfolio. The INM – Leibniz Institute for New Materials presents itself
in the German Pavilion (Booth E-18-24) at the nano tech 2011 in Tokyo
from 16th to 18th February 2011.
