Enhanced Bifacial III–V/Silicon Multijunction Solar-Cell-Based Promising Structure of c-Si Bottom Cells
Alamgeer Alamgeer, Polgampola Chamani Madara, Muhammad Quddamah Khokhar, Hasnain Yousuf, Jaljalalul Abedin Jony, Rafi Ur Rahman, Junhan Bae, Seokjin Jang, Min‐Kyung Shin, Sangheon Park, Junsin Yi
Abstract
We present a structural design for a four-terminal III–V/crystalline silicon (c-Si) multijunction (MJ) device based on optimized bifacial illumination. The proposed configuration consists of a triple-junction top cell incorporating gallium indium phosphide (GaInP), indium gallium arsenide (InGaAs), and germanium (Ge), paired with a tunnel oxide passivating contact (TOPCon) as the bottom cell. The bifacial TOPCon cell effectively enhances the transmission of albedo-reflected light into the c-Si absorber, delivering superior performance compared to conventional heterojunction cells. With an additional rear illumination of 0.3 sun, the bottom cell efficiency increases by 9.61%. Bifacial illumination enhances the overall efficiency of the MJ device by 20.77% compared to the monofacial device. With the power conversion efficiency (PCE) of bifacial GaInP/InGaAs/Ge/TOPCon MJ devices reaching 35.70%, this design demonstrates significant potential for advancing high-efficiency bifacial solar cell technologies.