Christian Wagner, Forschungszentrum Juelich (image) Forschungszentrum Juelich Share Print E-Mail Caption This is Dr. Christian Wagner with a model of the PTCDA molecule, which serves as a quantum dot . Credit Forschungszentrum Jülich / Sascha Kreklau Usage Restrictions Please give credit. Share Print E-Mail 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.