Performance improvement of III–V compound solar cells using nanomesh electrode and nanostructured antireflection structures

•Nanomesh electrode and nanorod array antireflection layer were designed.•Matching reflective index of TiO2 nanorod array was designed.•Various TiO2 nanorod arrays were deposited using oblique evaporation method.•Best efficiency of solar cell with nanomesh electrode and nanorod array was 37%. To improve the conversion efficiency of InGaP/InGaAs/Ge triple-junction solar cells, AuGeNi/Au nanomesh electrode structure and TiO2 nanostructured antireflection structure were designed and fabricated. Laser interference photolithography system was used to pattern 330-nm-wide nanomesh electrode structures with various AuGeNi/Au metal line intervals. Oblique evaporation method using electron beam evaporator was used to deposit TiO2 nanorod arrays with various periods. By using the AuGeNi/Au nanomesh electrode structure with metal line interval of 100 μm, the conversion efficiency of the InGaP/InGaAs/Ge triple-junction solar cells was improved to 35.25% compared with 30.84% of that with conventional bus-bar electrode structure. By using the TiO2 nanorod array with a period of 1.00 μm to replace the TiO2/SiO2 antireflection structure, the conversion efficiency was further improved from 35.25% to 37.00%.