Demonstration of GaAs‐Based Photovoltaics on Acoustically Spalled Surfaces Grown by MOCVD

ABSTRACT This study demonstrates the potential of sonic lift‐off (SLO) technology for repeatable substrate reuse in gallium arsenide (GaAs)–based photovoltaics (PVs), offering a pathway toward cost effective production for terrestrial PV applications. Single‐junction GaAs solar cells fabricated on acoustically spalled substrates achieved performance metrics comparable with those grown on standard commercial substrates, exhibiting short‐circuit current densities () of approximately 26.2–26.4 mA/cm 2 , open‐circuit voltages () around 1001 mV, fill factors (FFs) of 84%, and AM1.5G efficiencies near 22%. These results confirm that one reuse cycle can be realized without a performance penalty, offering a direct pathway to reducing substrate cost in fabrication. However, subsequent reuse of the substrates highlighted critical challenges, as devices fabricated from reused substrates showed significant degradation in performance ( of 15.5 mA/cm 2 , of 748 mV, FF of 72%, and efficiency of 8%), primarily due to degradation of the epitaxial structure resulting from repeated spalling cycles.