Performance Improvement of (NH[sub 4])[sub 2]S[sub x]-Treated III–V Compounds Multijunction Solar Cell Using Surface Treatment

To improve the conversion efficiency of tandem-type III–V multijunction solar cells, the –treatment method was used to passivate the surface of the window layer (AlInP) of the cell. The conversion efficiency of the -treated multijunction solar cell was increased more than 4%. Using X-ray photoelectron spectroscopy and current–voltage measurements, the mechanism of the conversion efficiency improvement is attributed to the reduction of the surface states by sulfidation passivation. It is indicated that the treatment is an effective method for improving the performance of III–V compound multijunction solar cells.