Electrically conductive anti-reflecting nanostructure for chalcogenide thin-film solar cells

Electrically conducting aluminum (Al)‐doped ZnO nanorods (NRs) film has been introduced as an anti‐reflective (AR) layer for effective light trapping in chalcogenide thin‐film solar cells. Results indicate that the Al‐doping significantly reduced the electrical contact resistance between the Ag top electrode and the AR layer. The Al‐doped ZnO NRs exhibited low average reflectance (4.5%) over the entire visible and near‐infrared range, and changed the nature of electrical contact between the Ag electrode and the AR layer from Schottky to Ohmic. Finally, the CuInS2 solar cell coated with the Al‐doped ZnO NRs exhibited huge enhancement in photovoltaic efficiency from 9.57% to 11.70% due to the lowering series resistance and the increase in the short‐circuit current density, when compared with that of a solar cell without the AR layer. Copyright © 2014 John Wiley & Sons, Ltd. Three types of CuInS2 solar cells, without ZnO NRs (reference), undoped ZnO NRs, and Al‐doped ZnO NRs were prepared. Comparing to the reference, the solar cells with the NRs showed lower total reflectance and higher photovoltaic efficiency. In case of the solar cell with Al‐doped ZnO NRs showed the highest photovoltaic efficiency, 11.70%.