A bioinspired Au-Cu1.97S/Cu2S film with efficient low-angle-dependent and thermal-assisted photodetection properties

Inspired by the geological processes, this study develops an innovative low-concentration-ratio H-2 reduction method to reduce the stoichiometric Au-CuS nanoparticles to produce completely reduced stoichiometric Cu2S with invisible'' Au achieved for solid solution Au enhancement. A stable Au-Cu1.97S/Cu2S micro/nano-composite is then formed by spontaneous oxidation. From this composite, in combination with biomimetic technology, an omnidirectional photoabsorption and thermoregulated film (Au-Cu1.97S/Cu2S-C-T_FW) is designed and fabricated as a photothermal-assisted and temperature-autoregulated photodetector for broadband and low-angle-dependent photodetection that presents good performance with high responsivity (26.37 mA/W), detectivity (1.25x10(8) Jones), and good stability at low bias (0.5 V). Solid solution Au exhibits significantly enhanced photodetection (1,000 times). This study offers a new concept for improving the stability and photoelectric properties of copper chalcogenides. Moreover, it opens up a new avenue toward enhancing the performance of optoelectronic and photovoltaic devices using solid solution metal atoms and thermal-assisted, anti-overheating temperature autoregulation.

Automated summary

This study introduces a novel low-concentration-ratio H-2 reduction method to produce highly efficient photodetectors by reducing Au-CuS nanoparticles to Cu2S with solid solution Au enhancement. The resulting omnidirectional photoabsorption and thermoregulated film shows excellent performance in photodetection with high responsivity, detectivity, and stability at low bias. The use of solid solution Au significantly enhances the photodetection performance, opening up new possibilities for improving optoelectronic and photovoltaic devices.