Abstract
Periodically patterned co-integration of silicon microwires (MWs) and nanowires (NWs) were applied for a novel photovoltaic (PV) nanodevice. The optical improvement due to antireflection enhancement with a graded-refractive-index (GRI) effect (see Fig. 1) was observed by employing the tapered NWs. Si MWs that formed a radial p-n junction were located in between the dense array of Si NWs. These wire arrays were cost-effectively defined by metal-assisted electroless wet etching. The co-integrated nanostructure of Si NWs and MWs demonstrated a high short circuit current (J(sc)) and cell conversion efficiency (CE) compared to a sole array of Si NWs or MWs. Highest values of J(sc) and CE at 1.5AM illumination were recorded as 24.89 mA/cm(2) and 8.45%, respectively, which have been champion data reported to date in wire based PV cells using a radial p-n junction.