Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
, 16 (9), 5358-64

Ultrathin Epitaxial Silicon Solar Cells With Inverted Nanopyramid Arrays for Efficient Light Trapping

Affiliations

Ultrathin Epitaxial Silicon Solar Cells With Inverted Nanopyramid Arrays for Efficient Light Trapping

Alexandre Gaucher et al. Nano Lett.

Abstract

Ultrathin c-Si solar cells have the potential to drastically reduce costs by saving raw material while maintaining good efficiencies thanks to the excellent quality of monocrystalline silicon. However, efficient light trapping strategies must be implemented to achieve high short-circuit currents. We report on the fabrication of both planar and patterned ultrathin c-Si solar cells on glass using low temperature (T < 275 °C), low-cost, and scalable techniques. Epitaxial c-Si layers are grown by PECVD at 160 °C and transferred on a glass substrate by anodic bonding and mechanical cleavage. A silver back mirror is combined with a front texturation based on an inverted nanopyramid array fabricated by nanoimprint lithography and wet etching. We demonstrate a short-circuit current density of 25.3 mA/cm(2) for an equivalent thickness of only 2.75 μm. External quantum efficiency (EQE) measurements are in very good agreement with FDTD simulations. We infer an optical path enhancement of 10 in the long wavelength range. A simple propagation model reveals that the low photon escape probability of 25% is the key factor in the light trapping mechanism. The main limitations of our current technology and the potential efficiencies achievable with contact optimization are discussed.

Keywords: crystalline silicon; light trapping; low-temperature epitaxy; nanoimprint lithography; solar cells.

Similar articles

See all similar articles

Cited by 3 PubMed Central articles

Publication types

LinkOut - more resources

Feedback