Front surface engineering of high efficiency Si solar cells and Ge TPV cells

We demonstrate the effectiveness of using wet chemical techniques for Si and Ge planar surfaces to form nanoporous layers, and grow stable passivating oxide layers on planar and porous surfaces, after the front grid metallization step. Our results show that this passivated chemical oxide layer: (i) can serve as an effective window/first layer AR coating, (ii) is chemically, thermally and UV stable, (iii) can simplify the structure of Si, Ge and III-V based space solar cells, thereby reducing cost, and (iv) has the potential of improving the BOL and especially the EOL efficiency of Si and III-V based space solar cells.