Details

Autor(en) / Beteiligte

• Anttu, Nicklas
• Dagyt, Vilgail
• Zeng, Xulu
• Otnes, Gaute
• Borgström, Magnus

Titel

Absorption and transmission of light in III-V nanowire arrays for tandem solar cell applications

Ist Teil von

• Nanotechnology, 2017-05, Vol.28 (20), p.205203-205203

Ort / Verlag

England: IOP Publishing

Erscheinungsjahr

2017

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• III-V semiconductor nanowires are a platform for next-generation photovoltaics. An interesting research direction is to embed a nanowire array in a transparent polymer, either to act as a stand-alone flexible solar cell, or to be stacked on top of a conventional Si bottom cell to create a tandem structure. To optimize the tandem cell performance, high energy photons should be absorbed in the nanowires whereas low energy photons should be transmitted to and absorbed in the Si cell. Here, through optical measurements on 1.95 eV bandgap GaInP nanowire arrays embedded in a polymer membrane, we identify two mechanisms that could be detrimental for the performance of the tandem cell. First, the Au particles used in the nanowire synthesis can absorb >50% of the low-energy photons, leading to a <40% transmittance, even though the Au particles cover <15% of the surface area. The removal of the Au particles can recover the transmission of low energy photons to >80%. Second, after the removal of the Au particles, a 40% reflectance peak shows up due to resonant back-scattering of light from in-plane waveguide modes. To avoid the excitation of these optical modes in the nanowire array, we propose to limit the pitch of the nanowire array.