We introduce single layer silicon dioxide (SiO2) nanosphere arrays as antireflection coatings (ARCs) on a gallium arsenide (GaAs) solar cell. We make macro- and nanoscale experiments and finite-difference time-domain (FDTD) calculations to prove the enhanced optoelectronic properties. The absorptivity enhancement of ~25% is achieved due to the combination of the resonant coupling of excited whispering gallery-like modes and the thin-film interference effects. The resonant coupling is masked in macroscale measurements by the nanosphere size variation, but it is clearly seen through imaging photocurrent on nanoscale. The usefulness of this ARC is also proved by investigating its performance as a function of irradiation angle. Because this ARC is made with inexpensive and scalable deposition methods that can be readily integrated with multiple solar cell technology, we evaluate an impact of manufacturing defects such as double layer formation. While its performance degrades, the ARC still offers marked improvement in comparison with bare cells.
Particle & Particle Systems Characterization