Enhanced absorption by nanostructured silicon

S. Bandiera (1) , D. Jacob (1) , T. Muller (1) , François Marquier (1, 2) , Marine Laroche (1) , Jean-Jacques Greffet (2, 1)

1 EM2C - Laboratoire d'Énergétique Moléculaire et Macroscopique, Combustion
2 Laboratoire Charles Fabry de l'Institut d'Optique / Naphel

Some applications such as ultrafast detectors or high efficiency photovoltaics require absorption by thin films. However, close to the bandgap, silicon absorbs very poorly. In this letter, we show that the absorption of a 100 nm slab can be as high as 50% in the range of wavelengths 700-830 nm when using a periodic structure properly designed.

Domaines: Optique [physics.optics]

S. Bandiera, D. Jacob, T. Muller, François Marquier, Marine Laroche, et al.. Enhanced absorption by nanostructured silicon. Applied Physics Letters, 2008, 93 (19), pp.193103. ⟨10.1063/1.3021480⟩. ⟨hal-00574367⟩