title: Improving thin-film crystalline silicon solar cell efficiencies with photonic crystals.
abstract: Most photovoltaic (solar) cells are made from crystalline silicon (c-Si), which has an indirect band gap. This gives rise to weak absorption of one-third of usable solar photons. Therefore, improved light trapping schemes are needed, particularly for c-Si thin film solar cells. Here, a photonic crystal-based light-trapping approach is analyzed and compared to previous approaches. For a solar cell made of a 2 mum thin film of c-Si and a 6 bilayer distributed Bragg reflector (DBR) in the back, power generation can be enhanced by a relative amount of 24.0% by adding a 1D grating, 26.3% by replacing the DBR with a six-period triangular photonic crystal made of air holes in silicon, 31.3% by a DBR plus 2D grating, and 26.5% by replacing it with an eight-period inverse opal photonic crystal.
authors: Peter
authors: P
authors: Bermel
authors: Chiyan
authors: C
authors: Luo
authors: Lirong
authors: L
authors: Zeng
authors: Lionel C
authors: LC
authors: Kimerling
authors: John D
authors: JD
authors: Joannopoulos