title: Optical absorption enhancement in a hybrid system photonic crystal - thin substrate for photovoltaic applications.
abstract: A hybrid approach for light trapping using photonic crystal nanostructures (nanorods, nanopillars or nanoholes) on top of an ultra thin film as a substrate is presented. The combination of a nanopatterned layer with a thin substrate shows an enhanced optical absorption than equivalent films without patterning and can compete in performance with nanostructured systems without a substrate. The designs are tested in four relevant materials: amorphous silicon (a-Si), crystalline silicon (Si), gallium arsenide (GaAs) and indium phosphide (InP). A consistent enhancement is observed for all of the materials when using a thin hybrid system (300 nm) even compared to the non patterned thin film with an anti-reflective coating (ARC). A realistic solar cell structure composed of a hybrid system with a layer of indium tin oxide (ITO) an ARC and a back metal layer is performed, showing an 18% of improvement for the nanostructured device.
authors: IMM-Instituto de Microelectrnica de Madrid, (CNM-CSIC), Isaac Newton 8, PTM, E-28760 Tres Cantos, Madrid, Spain. jeronimo.buencuerpo@imm.cnm.csic.es
authors: Jeronimo
authors: J
authors: Buencuerpo
authors: Luis E
authors: LE
authors: Munioz-Camuniez
authors: Maria L
authors: ML
authors: Dotor
authors: Pablo A
authors: PA
authors: Postigo