Optical design for 2-terminal III-V/Si SMAC module

A static concentrator lens was designed for 2-terminal GaAs/Si SMAC module, in which a GaAs subcell is mechanically stacked on a Si subcell. The Si cell has a larger active area than the GaAs subcell. Energy losses due to a current mismatch and electrodes shadow were considered. The designed lens shows a low peak angular optical efficiency but larger acceptance half angle, achieving annual energy collection efficiency of 75.7% for the module tilt angle of 35°. The prototype module was fabricated to verify the simulation. The measured short-circuit current of prototype SMAC module was close to the simulation results.