A silicon-based metamaterial for light-to-electricity conversion

摘要

One of the most challenging topics of today's research and development concerns efficiency of light-to-electricity conversion, preferably on Si-derived devices. The best of the possible/imaginable solutions has to allow overcoming the indirect Si bandgap constraints. This aim becomes realizable by transforming the hard photon-matter interaction into a soft photon-electron-electron interaction with additional new low-energy mechanisms to allow a multistage conversion cycle. Such effects have been observed by us within new Si-derived metamaterials obtained by multiple transformations, leading to a nanoscale Si-layered system. In such systems, a giant photoconversion could be observed for the first time due to hot electron interactions with active interfaces and conditioned crystalline defects transformed into Si metamaterial units, called tectons. Today it seems to be the best way to overcome conversion shortages of the bulk, thinfilm or any other Si-based devices. We present in this work a background and three experimental demonstrations of giant photoconversion