The challenges in front of PETE (photon-enhanced thermionic emission for solar concentrators) electrode synthesis are considered in this study. Composite PS (porous silicon) layers are suggested as a perspective material for PETE cathode realization due to the possibility to modify their band gap in a wide range from 1 to 3 eV and extensive capabilities for surface functionalization allowing for the variability of electron work function from the surface of the material. UV-Vis spectroscopy was used in order to characterize the surface structure of PS/Ag layers. The efficiency of thermionic energy conversion (TEC) is also analyzed, the problem of low electron work function material synthesis is acknowledged. In that regard the dynamic cesium flow technique is realized in order to create a novel nanostructured anode based on Ni covered with Cs - intercalated graphene layers. The electron work function lowering effect (up to 1 eV) is observed within this structure, leading to an overall increase in TEC efficiency to the value of 20% at ТЕ = 1570 K and ТС = 670 K.