Formation of nanostructured emitter for silicon solar cells using catalytic silver nanoparticles

► Nanoporous silicon was made on the emitter by size-controlled Ag nanoparticles catalyzed etching. ► The reflectivity of the nanoporous surface and electrical properties of the solar cells were characterized. ► The efficiency improvement was mainly due to the significantly increasing of short-circuit current. ► We report a nanoporous silicon solar cell with a 15.7%-efficiency without any passivation coating.