The current photovoltaic industry is dominated by crystalline or poly-crystalline Si inuda planar pn-junction configuration. The use of silicon nanowire arrays (SiNWA) withinudthis industry has shown great promise due to its application as an anti-reflective layer,udas well as benefits in charge carrier extraction. In this work, we use a metal assistedudchemical etch process to fabricate SiNWAs onto a dense periodic array of pyramids thatudare formed using an alkaline etch masked with an oxide layer. The hybrid micro-nanoudstructure acts as an anti-reflective coating with experimental reflectivity below 1% overudthe visible and near-infrared spectral regions. This represents an improvement of up toud11 and 14 times compared to the pyramid array and SiNWAs on bulk, respectively. Inudaddition to the experimental work, we optically simulate the hybrid structure using theudcommercial Lumerical FDTD package. The results of the optical simulations support ourudexperimental work, illustrating a reduced reflectivity in the hybrid structure. The nanowireudarray increases the absorbed carrier density within the pyramid by providing a guidedudtransition of the refractive index along the light path from air into the silicon. Furthermore,udelectrical simulations which take into account surface and Auger recombination show anudeffi ciency increase for the hybrid structure of 56% over bulk, 11% over pyramid array andud8.5% over SiNWAs. Opto-electronic modelling was performed by establishing a tool udflow to integrate the eff ective optical simulator Lumerical FDTD with the excellent fabrication andudelectrical simulation capability of Sentaurus TCAD. Interfacing between the two packagesudis achieved through tool command language and Matlab, off ering fast and accurate electro-opticaludcharacteristics of nano-structured PV devices.
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