(IMAGE) Technical University of Munich (TUM) Caption Filled with suitable organic polymers the highly porous germanium nanofilm becomes a hybrid solar cell. Because the germanium nanostructure forms an inverse opal-structure, the material shimmers like opal. Credit Andreas Battenberg / TUM Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.