Underwater Multispectral Computational Imaging Based on a Broadband Water-Resistant Sb₂Se₃ Heterojunction Photodetector

Exploration, utilization, and protection of marine resources are of great significance to the survival and development of mankind. However, currently classical optical cameras suffer information loss, low contrast, and color distortion due to the absorption and scattering nature for the underwater environment. Here, we demonstrate an underwater multispectral computational imaging system combined with single-photodetector imaging algorithm technology and a CdS/Sb2Se3 heterojunction photodetector. The computational imaging technology coupled with an advanced Fourier algorithm can capture a scene by a single photodetector without spatial resolution that avoids the need to rely on high-density detectors array and bulky optical components in traditional imaging systems. This convenient computational imaging method provides more flexible possibilities for underwater imaging and promises to give more imaging capabilities (such as multispectral imaging, antiscattering imaging capability) to meet ever-changing demand of underwater imaging. In addition, the water-resistant CdS/Sb2Se3 heterojunction photodetector fabricated by the close spaced sublimation (Sb2Se3) and chemical bath deposition (CdS) shows excellent self-powered photodetection performance at zero bias with high LDR of 128 dB, broadband response spectrum range of 300–1050 nm, high responsivity up to 0.47 A/W, and high specific detectivity over 5 × 1012 jones. Compared with the traditional optical imaging system, our designed computational imaging system that combines the advanced Fourier algorithm and a high-performance CdS/Sb2Se3 heterojunction photodetector exhibits outstanding antiscattering imaging capability (shielded by frosted glass), weak light imaging capability (∼0.2 μW/cm2, corresponding to moonlight intensity), and multispectral imaging capability. Therefore, we believe that this work will boost the progress of marine science.