In this study, we design the InGaP/GaAs/Ge triplejunction solar cells by optimizing short-circuit current matching between top and middle cells using Crosslight APSYS software. The base thickness of top InGaP cell is optimized at 0.36 um and the base thickness of middle GaAs cell is optimized at 3.2 um under AM1.5G illumination. For the optimized solar cell with nanorod arrays surface texture structure, the maximum I sc is 13.512 mA/cm 2 , the open-circuit voltage (V oc ) is 2.614 V, and the conversion efficiency (Ș) is 30.686 %. The enhancement of the I sc and the efficiency were 13.68 % and 12.24 %.