The potential of SWCNTs to extend the IR-absorption of silicon solar cells

Single wall carbon nanotubes (SWCNTs) have long been proposed as a candidate to enhance existing photovoltaic materials by providing an extension to the light absorbed in the infrared. In this work, we discuss the validity of this statement for silicon solar cells and couple a bifacial silicon solar cell to an organic SWCNT cell in a 4-terminal stack. Single chiral species of (6,5), (7,6), and (10,3) are used in the organic cell and the overall contribution to photocurrent from the SWCNTs is discussed in terms of the diameter dependent quantum efficiency, film thickness, the transmittance of silicon, the spectral overlap of the SWCNT's absorbance with the solar irradiance spectrum and the maximum obtainable current density in the infrared.