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%.
This work was supported from the Ministry of Science and Technology of the Republic of China under contract Nos. MOST 105-2221-E-006-199-MY3 and MOST 106-2923-E-155-001-MY2 , and from the framework international cooperation program managed by the National Research Foundation of Korea under NRF-2017K2A9A1A06057314 .
