(IMAGE) Kobe University Caption A solar cell structure using a hetero interface and the up-conversion of the two-proton system (yellow and red arrows). The light represented by the red and yellow arrows normally passes through when only a semiconductor is used, but with this system the light is absorbed, greatly increasingly the flow of electricity. Credit Kobe University 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.