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Improving Dielectric Nanoresonator Array Coatings for Solar Cells
Author(s) -
Ha Dongheon,
Zhitenev Nikolai B.
Publication year - 2018
Publication title -
particle and particle systems characterization
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.877
H-Index - 56
eISSN - 1521-4117
pISSN - 0934-0866
DOI - 10.1002/ppsc.201800131
Subject(s) - materials science , photocurrent , optoelectronics , dielectric , nanoscopic scale , gallium arsenide , coupling (piping) , coating , silicon , nanotechnology , composite material
Antireflection coatings based on dielectric nanosphere arrays are discussed in application to photovoltaic materials including silicon and gallium arsenide. Macro‐ and nanoscale characterizations and finite‐difference time‐domain calculations are performed, and demonstrate the enhanced optoelectronic properties. A significant absorptivity enhancement is achieved due to the collective resonant coupling of excited whispering gallery‐like modes and thin‐film interference effects. The resonant coupling is masked in macroscale measurements by the size variation of nanospheres, but it is clearly seen through imaging photocurrent at the nanoscale with near‐field scanning photocurrent microscopy. The resonant coupling can be effectively tuned by the material, configuration, or size of nanospheres. Hybrid coatings combining nanospheres of different materials yield the highest efficiency gain of more than 30%. The impact of manufacturing defects, such as double layer formation, is also evaluated. While the performance degrades, the antireflection coating still offers marked improvement in comparison with bare cells.