Fundamental limit of nanophotonic light trapping in solar cells.

ABSTRACT: 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)?, where n is the refractive index of the active layer, and ? 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 exhibit deep-subwavelength-scale field confinement, opening new avenues for highly efficient next-generation solar cells.

SUBMITTER: Yu Z 

PROVIDER: S-EPMC2955111 | biostudies-literature | 2010 Oct

REPOSITORIES: biostudies-literature