We show via numerical simulations that the absorption and solar energy conversion efficiency of a\r thin-film photovoltaic (PV) cell can be significantly enhanced by embedding it into an optical\r cavity. A reflective hemi-ellipsoid with an aperture for sunlight placed over a tilted PV cell\r reflects unabsorbed photons back to the cell, allowing for multiple opportunities for absorption.\r Ray tracing simulations predict that with the proposed cavity a textured thin-film silicon cell can\r exceed the Yablonovitch (Lambertian) limit for absorption across a broad wavelength range, while the\r performance of the cavity-embedded planar PV cell approaches that of the cell with the surface\r texturing.
Weinstein, L. A., Hsu, W. C., Yerci, S., Boriskina, S. V., & Chen, G. (2015). Enhanced absorption of thin-film photovoltaic cells using an optical cavity. Journal of Optics (United Kingdom), 17(5). https://doi.org/10.1088/2040-8978/17/5/055901