ReS₂ on GaN Photodetector Using H⁺ Ion-Cut Technology

The wafer-scale single-crystal GaN film was transferred from a commercial bulk GaN wafer onto a Si (100) substrate by combining ion-cut and surface-activated bonding. Well-defined, uniformly thick, and large-scale wafer size ReS₂ multilayers were grown on the GaN substrate. Finally, ReS₂ photodetectors were fabricated on GaN and sapphire substrates, respectively, and their performances were compared. Due to the polarization effect of GaN, the ReS₂/GaN photodetector showed better performance. The ReS₂/GaN photodetector has a responsivity of 40.12 A/W, while ReS₂/sapphire has a responsivity of 0.17 A/W. In addition, the ReS₂/GaN photodetector properties have reached an excellent reasonable level, including a photoconductive gain of 447.30, noise-equivalent power of 1.80 × 10^-14 W/Hz^1/2, and detectivity of 1.21 × 10¹⁰ Jones. This study expands the way to enhance the performance of ReS₂ photodetectors.