Synthesis and morphological control of self-powered broadband photodetector material: A study of bottle brush Co3O4/ZnO heterojunction

Self-powered broadband photodetectors operating in the ultraviolet–visible–near infrared (UV–Vis–NIR) range are pivotal for various applications, including optical communication, military surveillance, multispectral sensing, and environmental monitoring. In this study, we present an innovative approach to fabricate a bottlebrush nanostructure employing the Co3O4/ZnO PN junction. This unique design allows the photodetector to function efficiently without bias condi-tions, providing a versatile platform for a wide range of detection capabilities. The morphology of the photodetector is precisely controlled by manipulating the concentration of the growth solution containing cobalt tetroxide. Specifically, maintaining a concentration of 10 mM results in a well-defined bottlebrush heterojunction that exhibits highly efficient detection performance in the UV–Vis–NIR region. The maximum achievable responsivity (R) and specific detectivity. (D) are noteworthy, reaching values of 103.3 mA W−1 and 1.58 × 1014 Jones, respectively. These findings present a novel strategy for developing broadband photodetectors based on stable, nontoxic, and cost-effective metal oxides, opening new possibilities for advancements in photodetection technology. •Co3O4/ZnO bottlebrush enables bias-free UV-Vis-NIR detection. Outstanding results (R: 103.3 mA-1, D: 1.58×1014 Jones) advance metal oxide detectors.