Improvement of ZnO nanorod-based dye-sensitized solar cell efficiency by Al-doping

The current study investigates the performance of dye-sensitized solar cells (DSSCs) based on Al-doped and undoped ZnO nanorod arrays synthesized by a simple hydrothermal method Current density-voltage (J-V) characterizations indicate that Al-doping in ZnO crystal structure can significantly Improve current densities and the energy conversion efficiency (eta) of ZnO nanorod-based DSSCs The maximum eta 1 34% was achieved in DSSC when Al-doped ZnO nanorod arrays were grown in 004 M zinc acetate dihydrate solution with 5 mM aluminum nitrate nonahydrate This result represents a large Increase of eta in Al-doped ZnO nanorod-based DSSCs as compared to undoped (0 05%) The improved DSSC photovoltaic performance can be attributed to two main factors (1) increased light harvesting efficiency due to a large amount of N719 adsorbed on the large surface area of Al-doped ZnO nanorod arrays and (2) increased electrical conductivity due to Al3+ ion doped into the ZnO lattice at the divalent Zn2+ site allowing electrons to move easily into the Al-doped ZnO conduction band (C) 2010 Elsevier Ltd All rights reserved