Band engineering of Ni1-xMgxO alloys for photocathodes of high efficiency dye-sensitized solar cells
Junkai Deng, Majid Mortazavi, NV Medhekar, Jefferson Zhe Liu
Journal of Applied Physics | AMER INST PHYSICS | Published : 2012
Density functional theory calculations were carried out for Ni 1-xMgxO alloys using both GGA+U method and hybrid exchange-correlation functional HSE06. We find that the band gap of Ni1-xMgxO is a nonlinear function of MgO concentration with a strong bowing behavior at high Mg content. Band edge alignment is determined using heterojunction superlattice models. The valence-band-maximum of Ni1-xMgxO is shown to be tunable within a range of 0.90 eV. By comparing with the highest-occupied- molecular-orbital levels of some of the most widely used dye molecules, we propose that Ni1-xMgxO is a promising alternate to replace NiO photocathode in dye-sensitized solar cells with an enhanced open-circuit..View full abstract
We thank Y. F. Yin and W. C. Huang for helpful discussions. The authors gratefully acknowledge computational support from Monash University Sun Grid and the National Computing Infrastructure funded by the Australian Government.