Enhancing self-power broadband photodetection performance of Co₃O₄/ZnCo₂O₄/ZnO heterojunction via graphene oxide modification

In today’s field of optoelectronic devices, high-performance, self-power broadband responsive photodetectors hold significant application prospects and can find wide-ranging utility in areas such as optical communication, biomedical imaging, and environmental monitoring. This study investigates a series of samples with varying graphene oxide (GO) content, obtained through detailed characterization and optoelectronic performance testing. An appropriate amount of GO modification can form a thin film covering the brush-like Co 3 O 4 /ZnCo 2 O 4 /ZnO heterojunction surface, creating a conductive network. However, excessive content leads to GO aggregation on the heterojunction surface, affecting detection performance. Density functional theory (DFT) calculations elucidate the electron structure and transport mechanism at the interface between ZnO and GO, demonstrating graphene oxide’s efficacy as an electron transfer channel, thus enhancing the material’s optoelectronic detection performance. By employing the most suitable amount of GO modification, the optoelectronic detection performance of the Co 3 O 4 /ZnCo 2 O 4 /ZnO heterojunction is further improved. The maximum responsivity and detectivity under monochromatic light reach 193.33 mA/W and 3.68×10 13 Jones, respectively. This work provides significant insights for the design and manufacturing of optoelectronic devices, with crucial scientific significance and practical value.