High-efficiency III–V//Si tandem solar cells enabled by the Pd nanoparticle array-mediated “smart stack” approach

Smart stack is a handy technique to produce two-terminal tandem structures from various photovoltaic materials using Pd nanoparticle arrays as bonding mediators. Because of the increasing interest in III–V/Si integration, we herein demonstrated smart stack-based triple-junction cells consisting of InGaP/GaAs and crystalline Si subcells. Despite the use of classic Al-back surface field-type Si subcells, current matching with the InGaP/GaAs subcells was realized, and the promising efficiency of 25.1% was successfully achieved. The potential and versatility of the smart stack approach as a fabrication tool for high-efficiency multi-junction cells were further enhanced through this study.