AlxGa1-xAs/GaAs heterostructure has been grown by two different liquid phase epitaxy(LPE) methods for the fabrication of solar cells. Typical structure characteristics observed under transmission electron microscopy(TEM) and the corresponding device parameters are presented. The results indicate that the P+PNN+ configuration grown by meltback-regrowth method can effectively reduce the defects of the substrate and improve the minority carrier collection by forming a composition-graded region in the window layer. By optimizing the growth conditions and device technology
the best cell performance with conversion efficiency of 18. 78% under AMO