High-efficiency cells

In addition to silicon wafers and thin films, other photovoltaic technologies are gaining interest and importance such as concentrating PV technologies, in combination with very high-efficiency cells. 

Low efficiency cell designs (b) thin-layer (c) wall-jet. (d) High-efficiency cell design with porous working electrode in tube. Arrows indicate liquid flow... 

Matthews, G. M., and Colman, A. (1991) A highly efficient, cell-free translation/translocation system prepared from Xenopus eggs. Nucleic Acids Res. 19, 6405-6412. 

It is evident from our discussion that realizing the promise of high efficiency cells requires photovoltaically active semiconductors with band gaps in the range 1.0 to 2.4eV. Figure 5 tabulates the band gaps of some binary and ternary semiconductors which could serve as the photovoltaically active materials in the cells. These materials have discrete values of E, and while it may be possible to identify a group of them for a specific tandem cell system. 

---