Planares Schwarzes Silizium

The state of the art nanotexturing of a solar cell’s absorber material lead to a strong and
spectrally broadband enhancement of the absorption of incident sun light. However, the
nanotexturing of the interfaces degrades simultaneously the electrical properties of the optoelectronic
device. This denies the complete harvest of the absorption improvement and
does not allow to translate it to a comparable improvement in device efficiency. In contrast,
external light trapping structures that leave the absorber material undamaged are optically
far from optimum and they provide substantially weaker absorption enhancement.
To solve this problem, we propose to capitalize on the notion of transformation optics (TO)
to perceive photonic structures that preserve the geometrical flatness of the absorber material,
to leave it electrically intact, while acting optically like a textured interface with optimized
scattering properties.