Porous silicon and graphene-based nanostructures for novel solar energy systems

Abstract

The investigation of composite porous silicon (PS) and graphene nanostructured materials for low work function PETE (photon-enhanced thermionic emission for solar concentrator systems) and thermionic plasma energy systems synthesis is reported in this article. These two types of materials are suggested for further development and study due to remarkable physical effects taking place in the aforementioned structures. The nature of low-work function phenomenon is discussed and interpreted as due to the influence of functionalization and synthesis parameters on the structure properties of composite materials. The Raman spectroscopy technique is utilized in order to characterize porous silicon based nanostructured composite layers (PS/Ag). The interpretation of PS/Ag Raman spectra is suggested. The significant decrease in the effective electron work function to an exceptionally low value of 1 eV is achieved with a perforated nickel collector functionalized with nanosized graphene layers. SEM X-ray microanalysis of the thermionic energy converter (TEC) collector surface is performed, the interpretation of the anode work function lowering effect is proposed.