In our group, efficiencies up to 18.8% on glass substrates were achieved. Flexible thin film solar cells on polymer film with a new record efficiency of 20.4% have been independently certified by Fraunhofer Institute for Solar Energy Systems (ISE) in Freiburg, Germany.
The 20.4% efficiency solar cell is an independently certified highest efficiency record for any type of flexible solar cell on polymer film reported up to now. Furthermore, it represents the highest reported efficiency of a CIGS solar cell on any type of substrate. This solar cell processing can be adapted for roll-to-roll maufacturing of monolithically interconnected solar modules on polymer films.