The Centre for Solar Energy and Hydrogen Research Baden-Württemberg (ZSW) has achieved a 22% conversion efficiency for a CIGS thin-film solar cell the highest yet recorded in Europe.
In December last year Japans Solar Frontier set a new world record of 22.3% CIGS efficiency on a 0.5cm x 0.5cm cell in test conditions to surpass ZSWs previous world record, but this latest improvement by the German research hub represents the first time a European team has reached 22% efficiency.
ZSW works alongside Germany equipment maker Manz AG, which manufactures commercial turnkey CIGS equipment for the industry, and although this 22% conversion ratio was achieved in optimized laboratory conditions on a 0.5cm-square test cell, ZSW board member and head of the PV division Michael Powalla is confident that greater efficiencies can be achieved and commercialized in the next few years.
"The technological potential is far from tapped out at 22% efficiency," he said. "It will be possible to achieve up to 25% in the next few years." Confirmation of the test results was verified by Fraunhofer ISE, and while this new efficiency record is a benchmark for Europe, commercially available CIGS modules are still only around 14% efficiency below the average 17% efficiency rates of traditional silicon PV modules.
In terms of manufacturing costs, CIGS modules can be developed for around $0.40/W, and global production capacity currently stands at 500 MW to 1 GW of CIGS. However, it is widely expected that thin-film production costs can be brought down significantly over the next few years, allied to steady efficiency increases. ZSW expects mass-produced CIGS on the market at costs of $.025/W and efficiencies of 18% with the current decade.