Moth‐eye antireflection coating fabricated by nanoimprint lithography on 1 eV dilute nitride solar cell

Abstract

We report on the performance of biomimicked antireflection coating applied to dilute nitride solar cell. The coating consists of nanostructures replicating the moth‐eye geometry and has been fabricated by nanoimprint lithography directly within the window layer covering the dilute nitride absorbing junction. The mean reflectivity within the spectral range of 320–1800 nm remains under 5% for incident angles up to 45°. The effect of the coating on the cell performance was assessed by measuring the current–voltage characteristics under simulated solar illumination. A clear performance increase was identified when comparing a solar cell with the moth‐eye coating with a solar cell having a standard SiNx/SiO2 coating. Copyright © 2012 John Wiley & Sons, Ltd.

Moth eye antireflection coated GaInP/GaAs/GaInNAs solar cell

“…The advantageous features of such nanostructures fabricated in AlInP, which is typically used as a window layer on GaAs based MJSCs, have been already demonstrated [3,4]. Moreover, we have also demonstrated a moth eye ARC fabricated on top of a single junction dilute nitride solar cell with a bandgap (E g ) of 1 eV [4].…”

“…In addition to the simulated reflectance in Ref. [4], the angular performance of the moth-eye-patterned 1 eV GaInNAs SC was also evaluated. The reflectance was found to remain below 5% up to incident angles of 45° and less than 10% even up to 60°.…”

“…The reference sample was e-beam coated with a TiO 2 /SiO 2 ARC. Details of the MJSC growth and the moth eye ARC fabrication have been reported elsewhere [3,4,13]. Ni/Ge/Au contact fingers and the Ti/Au back contact were deposited by e-beam evaporation on the n-side and p-side, respectively.…”

“…Moreover, we have also demonstrated a moth eye ARC fabricated on top of a single junction dilute nitride solar cell with a bandgap (E g ) of 1 eV [4]. For the sake of generality we note that there are also other materials that can be used as the basis for the moth eye pattern, for example polymers, semiconductor nanowires and patterned dielectrics [5,6,8,9,10,11,12].…”

Performace of Dilute Nitride Triple Junction Space Solar Cell Grown by MBE

“…Consequently, Ge junction is generating approximately only 0.2 V. Lattice matched 1 eV band-gap dilute nitrides, such as GaInNAsSb alloys, offer lower quantum defect and higher voltage generation. The best band-gap voltage offset value demonstrated for dilute nitride junction is 0.49 V [2]. Therefore, with current balanced ~1 eV dilute nitride junction, up to 0.3 V higher operation voltage could be produced than with Ge junction.…”