title: Semiconductor solar superabsorbers.
abstract: Understanding the maximal enhancement of solar absorption in semiconductor materials by light trapping promises the development of affordable solar cells. However, the conventional Lambertian limit is only valid for idealized material systems with weak absorption, and cannot hold for the typical semiconductor materials used in solar cells due to the substantial absorption of these materials. Herein we theoretically demonstrate the maximal solar absorption enhancement for semiconductor materials and elucidate the general design principle for light trapping structures to approach the theoretical maximum. By following the principles, we design a practical light trapping structure that can enable an ultrathin layer of semiconductor materials, for instance, 10 nm thick a-Si, absorb > 90% sunlight above the bandgap. The design has active materials with one order of magnitude less volume than any of the existing solar light trapping designs in literature. This work points towards the development of ultimate solar light trapping techniques.
authors: Department of Physics, North Carolina State University, Raleigh NC 27695.
authors: Yiling
authors: Y
authors: Yu
authors: Department of Materials Science and Engineering, North Carolina State University, Raleigh NC 27695.
authors: Lujun
authors: L
authors: Huang
authors: 1] Department of Materials Science and Engineering, North Carolina State University, Raleigh NC 27695 [2] Department of Physics, North Carolina State University, Raleigh NC 27695.
authors: Linyou
authors: L
authors: Cao