Fundamental limit of nanophotonic light trapping in solar cells

Establishing the fundamental limit of nanophotonic light-trapping schemes is of paramount importance and is becoming increasingly urgent for current solar cell research. The standard theory of light trapping demonstrated that absorption enhancement in a medium cannot exceed a factor of 4n(2)/sin(2)θ, where n is the refractive index of the active layer, and θ is the angle of the emission cone in the medium surrounding the cell. This theory, however, is not applicable in the nanophotonic regime. Here we develop a statistical temporal coupled-mode theory of light trapping based on a rigorous electromagnetic approach. Our theory reveals that the conventional limit can be substantially surpassed when optical modes…

• UD
  U.S. Department of Energy

  Awards: DE-FG02-07ER46426, FG02-07ER46426, DE-FG02-, DE-FG02
• KA
  King Abdullah University of Science and Technology