Weiss Dirk N, Lee Benjamin G, Richmond Dustin A, Nemeth William, Wang Qi, Keszler Douglas A, Branz Howard M
Washington Technology Center and University of Washington, Department of Electrical Engineering, Seattle, Washington 98195, USA.
Appl Opt. 2011 Oct 10;50(29):5728-34. doi: 10.1364/AO.50.005728.
Diffractive light trapping in 1.5 μm thick crystal silicon films is studied experimentally through hemispherical reflection measurements and theoretically through rigorous coupled-wave analysis modeling. The gratings were fabricated by nanoimprinting of dielectric precursor films. The model data, which match the experimental results well without the use of any fitting parameters, are used to extract the light trapping efficiency. Diffractive light trapping is studied as a function of incidence angle, and an enhancement of light absorption is found for incidence angles up to 50° for both TE and TM polarizations.
