Polarization Effect on the Photovoltaic Characteristics of $\hbox{Al}_{0.14}\hbox{Ga}_{0.86}\hbox{N}/\hbox{In}_{0.21}\hbox{Ga}_{0.79}\hbox{N}$ Superlattice Solar Cells

The influence of spontaneous and strain-induced piezoelectric polarizations on the photovoltaic characteristics of an Al
_0.14
Ga
_0.86
N/In
_0.21
Ga
_0.79
N superlattice (SL) solar cell is numerically investigated. The simulation results show that, compared with the conventional p-i-n structure, the Al
_0.14
Ga
_0.86
N/In
_0.21
Ga
_0.79
N SL solar cell has better photovoltaic characteristics and is less sensitive to the effect of internal polarization. Therefore, the use of an SL structure in the III-nitride solar cells is advantageous if both the polarization effect and the crystal quality are of major concern.